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LAND *

MACKAY SUGAR CANE LAND SUITABILITY STUDY

PART 2. LAND SUITABILITY

G.K. Holz and P.G. Shields

BpIDE PA RTMENT OF PM~I~RY INDUSTMES

L-l l l 11,'1-1 w:l ~1 , ]

Queensland Government Technical Report

This report is a scanned copy and some detail may be illegible or lost. Before acting on any

information, readers are strongly advised to ensure that numerals, percentages and details are correct.

This report is intended to provide information only on the subject under review. There are limitations

inherent in land resource studies, such as accuracy in relation to map scale and assumptions regarding

socio-economic factors for land evaluation. Before acting on the information conveyed in this report,

readers should ensure that they have received adequate professional information and advice specific to

their enquiry.

While all care has been taken in the preparation of this report neither the Queensland Government nor

its officers or staff accepts any responsibility for any loss or damage that may result from any

inaccuracy or omission in the information contained herein.

© State of Queensland 1985

For information about this report contact [email protected]

mailto:[email protected]

Queensland Department of Primary Industries Land Resource Bulletin QV85002

MACKAY SUGAR CAN

LAND SUITABILITY STUDY

PART 2. LAND SUITABILITY

G.K. Holz and P.G. Sh ie lds Land Resources Branch

Queensland Department of Primary Industries Brisbane 1985

ISSN 0All-9007

The significant contribution of operating funds and the provision of office accommodation provided by the Bureau of Sugar Experiment Stations for the conduct of this study is gratefully acknowledged.

The publication was produced in conjunction with Queensland Department of Primary Industries Land Resource Bulletin QV8500]

Queensland Department oF Primary Industries GPO Box 46 Brisbane 4001.

(iii)

CONTENTS

LIST OF ILLUSTRATIONS

LIST OF TABLES

SUMMARY

I ~. INTRODUCTION

2. THE MACKAY SUGAR INDUSTRY

2.1 Production characteristics 2.2 Eton Irrigation Scheme

3. METHODOLOGY

3.1 Assessing land suitability

3.2 Mapping assigned land 3.3 Storing and extracting data

. LAND SUITABILITY FOR GROWING SUGAR CANE

4.1 The classification scheme 4.2 Limitations to cane production

4.3 Suitability of unique map areas and soil mapping units

5. INTERPRETATION OF THE DATA

5.1 Mapping scale

5.2 Land use efficiency 5.3 Use of suitability classes

6. RESULTS

6.1 General

6.2 Total land suitable for sugar cane 6.3 Characteristics of assigned land 6.4 Characteristics of potential assigned land

7. CONCLUSIONS AND RECOMMENDATIONS

8. ACKNOWLEDGEMENTS

. REFERENCES

APPENDICES

I Explanation of codes for the uma data file II Unique map area data file (microfiche)

Page No.

V

vii

I

3

7

7

11

13

13 13 14

17

17 18

29

53

53 53 55

57

57 58

60 64

69

71

73

77

(v)

LIST OFILLUSTRATIONS

Page No.

Figure l.

2.

3.

.

.

Locality plan.

Tonnes 94 nt sugar produced by the six Mackay mills 1965-1982.

Average sugar yields and average ccs for the six Mackay mills 1965-1982.

Area harvested and area assigned for the six Mackay mills, 1965-1982.

Technique of overlaying soils on UMA base map.

5

9

12

15

Plate i.

2.

3.

4.

.

.

Urban development adjacent to caneland in North Mackay.

Soil conservation layouts on newly assigned land at Royston Park.

Low land use efficiency due to small blocks and unusable land on steep, uneven slopes.

A typical 'soda patch' where small areas of highly alkaline sodic soil severely affect cane growth.

Poor crop growth on marginal land in the Kinchant area because of moisture availability, soil nutrient, salinity and wetness limitations.

Landscaping in the Cattle Creek mill area includes bulldozing through a small hill in order to provide more land for assignment.

49

49

50

50

51

51

Map i.

2.

3.

Assigned Cane Land (February, 1980).

Land Suitability for Sugar Cane.

Land Use and Land Suitability.

(vi i )

LIST OF TABLES

Page No.

Table i.

2.

3.

4.

.

.

7.

8.

9.

i0.

ii.

12.

13.

14.

Yield comparisons of Queensland sugar producing districts, 1973-1982.

Mill peak, area of assigned land and number of cane suppliers to each mill, 1982.

Average cane yield, cane yield variability and average ccs for each mill, 1965-1982.

Irrigation statistics for each mill area, 1982.

Estimated assigned areas for each mill on uniform clay soils of alluvial plains.

Salinity standards for soils in the Queensland cane growing areas.

Relative erodibility ratings for Mackay soils.

The areas, major limitations and soils in each suitability class.

Mill factors for estimating assigned land.

Adjusted mill factors for each suitability

class.

Total area of land in Classes 1 to 4.

Total area (ha) and severity of each limitation.

Area of land in each suitability class assigned to each mill.

The percentage of land assigned to each mill affected by each limitation.

10

11

14

22

27

38

54

56

58

59

60

62

(viii)

LIST OF TABLES

Page No.

Table 15.

16.

17.

The percentage of assigned land within specified distances from each mill.

The area and severity of existing erosion on land assigned to each mill.

The area and suitability class of the potential assigned land.

18. Percentage distribution of suitability classes within assigned and potential assigned land.

19. Percentage distribution of limitations within assigned and potential assigned land.

20. The percentage of assigned and potential assigned lands within specified distances from the mills.

63

64

64

66

66

66

SUMMARY

The land resources of approximately 290 000 ha which have been mapped

and described for the Mackay area have been assessed in terms of land

suitability for growing sugar cane. Each of the 2 225 unique map areas

identified during the soil survey have been individually assessed for

their relative suitability for growing sugar cane.

The significant limitations to production were identified and

assessed for each unique map area. Limitations considered were climate,

moisture availability, soil nutrients, salinity and sodicity, soil

workability, stoniness, wetness, erosion and flooding.

Area data have been calculated for each land suitability class

using different land use efficiency factors for each class of land to

account for the varying proportions of the gross areas actually useable

for cane growing.

Three maps at a scale of i:i00 000 accompany this report and show -

assigned cane land, land suitability for sugar cane and land use and

land suitability.

The total (measured) area of class I, 2 and 3 land suitable for

growing sugar cane in the long term is 143 140 ha. A further 7 350 ha

are considered marginal for long term cane production. If all land

suitable for cane growing was available to the industry there is

sufficient class i, 2 and 3 land to facilitate an increase of 39 570 ha

in assigned land (after taking into account the land use efficiency

factors) indicating that there is substantial scope for expansion in

all mill areas except Cattle Creek.

Approximately 1 230 ha of currently assigned land is considered

unsuitable for growing sugar cane in the long term mainly aue to soil

erosion. Consideration should be given to the transfer of these

assignments to suitable unassigned areas. A further 1 400 ha of assigned

landsare considered marginal for growing sugar cane in the long term

and the continued use of this land for cane growing is questioned.

1. INTRODUCTION

The Mackay Sugar Cane Land Suitability Study began in 1979 in response to land use concerns affecting the sugar industry. The major concerns were the loss of both existing and potential caneland to alternative uses such as urban and industrial development and through erosion. Other considerations included expansion of cane growing onto marginal or unsuitable lands, the location of the lands assigned to each mill and the total cane growing potential of the district.

The steering committee for the study investigating urban expansion

effects on sugar cane land around Mackay (Ullman & Nolan 1978) recommended that 'the Department of Primary Industries, in consultation with the Bureau of Sugar Experiment Stations (BSES) and other industry organizations, should examine the need for a Mackay district land capability investigation to define the extent and relative suitability for cane growing of potentially available land'

Subsequent discussions with sugar industry groups established a need for information covering all the land assigned to and potentially available to the eight mills which comprise the central district. Consequently, the boundaries for this study were defined to cover Farleigh, Racecourse, Pleystowe, Marian, Cattle Creek and North Eton mill areas. Plane Creek and Proserpine mill areas will be covered by

separate studies.

The study area extends from Elaroo in the north to Alligator Creek in the south, between the Clark and Connors Ranges and the coastline.

Total area is approximately 290 000 ha (Figure i).

The approach adopted for the study was to compile a land resource inventory and then assess the suitability of these land resources for growing sugar cane. The study results are presented in two parts. Part One contains the Land Resource Inventory (Holz and Shields 1984). This report, Part Two, documents the land suitability for growing

sugar cane.

2. THE MACKAY SUGAR INDUSTRY

2.1 Production characteristics

The sugar industry began in Mackay in 1863 (Elliot and Pembroke 1949) and by the early 1870's there were 3 436 acres (i 391 ha) of cane supplying 35 small mills. In 1982, there were 76 272 ha of land assigned to 1 194 suppliers to six sugar mills.

Production statistics for the Mackay district compare favourably with those from other sugar producing areas in the state (Table i). Over the ten year period 1973-82, the Mackay district (including Plane Creek mill) averaged 73.8 tonnes cane/ha with a commercial cane sugar content (ccs) of 14.5%, i.e., 10.7 tonnes 94 net titre (nt) sugar/ha. Only the irrigated Burdekin and Bundaberg districts have higher yields.

Table i. Yield comparisons of Queensland sugar producing districts, 1973-1982

Average Sugar yield District ccs t 94 nt sugar/ha

harvested

Mossman-Ingham 12.9 10.2

Burdekin 14.5 17.1

Proserpine 14.4 10.5

Mackay 14.5 10.7

Bundaberg 13.9 11.4

Maryborough-Childers 13.5 9.4

Nambour-Beenleigh 13.1 9.8

Source: Australian Sugar Year Book and BSES Annual Report

There are six sugar mills in the study area. Farleigh, Racecourse, Marian, Cattle Creek and North Eton mills are co-operatives while Pleystowe is owned by CSR Ltd. The relative sizes of each of the six mills is given in Table 2.

Table 2. Mill peak, area of assigned land and number of cane suppliers to each mill, 1982

Mill Mill peak

(tonnes 94 nt sugar) Assigned Number

land of (ha) Suppliers

Farleigh

Racecourse

Pleystowe

Marian

Cattle Creek

North Eton

127 870 15 900 252

120 500 13 681 198

125 730 14 350 242

118 500 15 343 234

58 800 7 045 120

78 900 9 954 148

Source: Queensland Government Gazette and Sugar Journal

These six millsproduce around 20% of the sugar made in Queensland each year. Figure 2 shows the total sugar production from the six mills from 1965 to 1982. The fluctuations in output are due to seasonal conditions (yield and ccs) and the market for sugar and thus the level of crop acquisition. Figure 3 shows average sugar yields and average ccs fluctuations over the same period, 1965-1982.

In Table 3 the average cane yield, yield variability and average ccs are shown for each mill over the period 1965-1982. Racecourse and Pleystowe mills have consistently higher average yields while the high yield variability of North Eton mill indicates the mill areas' susceptibility to drought prior to the Eton Irrigation Scheme. Cattle Creek mill has a consistently lower ccs (around 0.5 of a unit) than

the other mills.

700

o 600 @ x

"E

500 I - -

/

65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 Year

Figure 2 Tonnes 94 nt sugar produced by the six Mackay mills 1965-1982

12.0

11.5

11.0

~10.5 u)

~=10.0

o t - -

9.5 / \

Average sugar yield

f On,t~ of

C , C . S ,

, , ( , 16.0

, , II~ ~ 15.5

/ ! , , , ~. '~ ~0o

/ �9 ~ 14.5

i" / ~ /Average c.c.s,

~/ , 4 .0

V

13.5 8.5

65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 Year

Figure3 Average sugar yields and average ccs for the six Mackay mills 1965-1982

10

Table 3. Average cane yield, cane yield variability and average ccs for each mill 1965-1982

Average cane Cane yield Average Mill yield t ha -I variability ccs

t ha -I

+ Farleigh 70.6 - 4.5 14.6

+ Racecourse 76.8 - 6.3 14.8

+ Pleystowe 75.6 - 5.1 14.9

+ Marian 68.3 - 5.6 14.6

+ Cattle Creek 70.8 - 7.0 14.1

North Eton 67.4 ~12.5 14.6

Source: BSES Annual Reports and Queensland

Canegrowers Association Annual Reports

The number of mill suppliers has been steadily declining because

of farm amalgamations. There were 248 fewer suppliers to the six mills in 1982 than in 1965.

Figure 4 compares the assigned area and the harvested area for the six Mackay mills from 1965 to 1982. The difference between the

two graphs measures mainly fallow land except for the years 1965, 1967, 1970, 1978 and 1979 when there was a substantial area of standover cane because of limited acquisition. A wet harvest in 1973 left a substantial area of cane unharvested. The proportion of fallow land has been gradually decreasing from 25% in 1966 to 15% in 1975 and 8%

in 1981.

The use of irrigation for soil management and yield stabilisation is increasing in the district. Data supplied by the cane inspectors

is given in Table 4 and gives some irrigation statistics for each

mill area.

11

Table 4. Irrigation statistics for each mill area, 1982

Number of Per cent of Per cent

Mill Hectares farmers assigned farmers irrigated with area with

irrigation irrigated irrigation

Farleigh 4 472 107 28% 42%

Racecourse 9 538 149 70% 75%

Pleystowe 8 190 147 57% 61%

Marian 5 181 ii0 34% 47%

Cattle Creek 2 993 49 42% 41%

North Eton 7 235 140 73% 95%

(approx.)

TOTAL 37 609 702 51% 60%

The benefit of irrigation is difficult to gauge from the above figures due to the varying capabilities (water supply, equipment) and the range of strategies employed by farmers. For example, the high proportion of irrigated land in North Eton reflects not only the requirements for irrigation but also the availability of adequate water supplies from the Eton Irrigation Scheme. In contrast, underground water supplies throughout most of the Farleigh mill area are limited. Some farmers with small supplies and limited to strategic watering over small areas are included in the above statistics.

2.2 Eton Irrigation Scheme

The Eton Irrigation Scheme began in 1974 and is as yet incomplete. The aim of the scheme is to supply irrigation water to the Eton - Brightley and Oakenden areas where occasional severe crop losses and

generally depressed yields occur due to drought conditions. The location of the scheme is shown on Map 2, 'Land Suitability for Sugar Cane'.

When complete, the scheme is designed to harvest water from the Pioneer River, store it in Kinchant dam and deliver it via 37 km of open channels and 102.2 km of pipelines to approximately 200 holdings and ii 000 ha of potential irrigation land.

A weir on the Pioneer River above Mirani will store 5 500 MI. A pump station capable of 860 Ml/day will pump water from the weir through an 8.2 km open channel to Kinchant dam.

Kinchant dam is an earthfili embankment offstream storage which will store 62 800 M1 when complete. The dam and associated works will cover 1 400 ha and it has a natural catchment of 3 200 ha.

80

70

W J ~ v o 60 o o

x

50

Assigned Area

S . t .

~~9~5de~ 7eoa'~in7~i ! r77~ Sl ifa ':~ 2 a~ du i i int~ ~ n ~ /

> ~ ~ # ' ~ ) ' ~ ~W~et H i rve s t

65 66 67 68 69 .70 71 72 73 74 75 76 77 78 79 80 81 82 Year Figure 4 Area harvested and area assigned for the six Mackay mills 1965-1982

13

3. METHODOLOGY

3.1 Assessing land suitability

A soil survey of the study area (Holz and Shields 1985) delineated 2 225 unique map areas. A unique map area (uma) contains similar soils and topography. The land resources of each uma were described on a computer file to form a land resource inventory.

The unique map areas have been individually assessed for their relative suitability for growing sugar cane using the land suitability classification scheme described in Section 4. The significant limitations to production were identified for each uma. The severity of each limitation was assessed on a 1 to 5 scale coinciding with the scheme's five suitability classes. The land was then placed into one of the five classes, generally determined by the most severe limitation identified. In some cases the combination of two or more limitations may have been sufficient to downgrade a uma to a less suitable class.

The significant limitations to production in the Mackay study area were identified following discussions with BSES staff, a literature review and field experience gained during the study.

The suitability class and the relevant limitations to production have been recorded on the computer data file containing the land

resource inventory.

3.2 Mapping assigned land

The assigned land was mapped so that the location, size and relative suitability of assigned land and unassigned land could be compared.

Cane inspectors from all mills in the study area delineated the assigned land as at February 1980, onto black and white aerial photographs (scales 1 : 24 000 and 1 : 28 000). These were compiled onto eight 1 : 50 000 working maps, with mill tramways also being shown. Following a later expansion, the assigned land was updated to June 1982, on both the aerial photographs and working maps.

The updated maps were overlain on the uma working maps. In each uma, the area of land assigned to each mill was measured with a digitiser and the area of unassigned land calculated.

14

Assigned land is measured by the cane inspectors at a scale of 1 : 4 000, thus the digitized areas measured at 1 : 50 000 over-

estimate the actual assigned area. In order to estimate the actual

assigned area, the 1 : 50 000 measured area was modified by a mill factor. Similarly, the measured area of suitable but unassigned land was modified by a land use efficiency factor. A complete explanation of mill factors and land use efficiency factors is given in Section 5, Interpretation of the Data.

3.3 Storing and extracting data

The computer based uma data file contains location data, the land resource inventory, land suitability assessment, and cane assignment

data. The uma data file is presented on microfiche in Appendix II. The land suitability and cane assignment data include the land

suitability class, the major limitations to cane production, the

total area of the uma, the estimated assigned area, the potential assigned area and the alienated area. The alienated area includes the

residue after applying the mill and land use efficiency factors to both

assigned and unassigned lands. The measured areas and mill identificat- ion are not included in Appendix II but are available on computer files.

This data can be manipulated and extracted in any combination. can be printed out in tables or in an overlay form. If needed, the

resource, land suitability and cane assignment information can be

extracted together.

It

Using the tabular form of data presentation, the required information can be sorted into groups, listed, areas summed and

statistically analysed. A simple example of tabular presentation is given in Table ii which shows the total area of suitable land in each of the four suitability classes. In a more complex example, Table 13

presents the suitability of land assigned to each mill.

As an example of how the land suitability and resource data can be integrated, Table 5 shows the areas of uniform clay soils of

alluvial plains that occur in each mill area.

Table 5. Estimated assigned areas for each mill on uniform clay soils of alluvial plains

Mill Area (ha)

Farleigh 2 099

Racecourse 1 903 Pleystowe 2 318 Marian 1 053

Cattle Creek 338

North Eton 2 862

15

The overlay form of data presentation involves plotting the required information at the grid co-ordinates of a labelling point located within each uma. A plotter plots the information at any scale which allows the user to choose an appropriate base map. Plots covering an entire I : 50 000 map of 70 cm x 85 cm can be produced.

Figure 5 shows how data plotted at the grid co-ordinates of the labell~ng point for each uma can be overlayed on a base map to show its spatial distribution.

The information stored on computer files can be accessed by contacting the Director, Land Resources Branch, Department of Primary Industries, Meiers Road, Indooroopilly, 4068.

UMA base map

305

303

1077

319

Sg

MT

Compos i te

GU Sg

C lear ove r lay

MT

GU

MT Ro

Vc

Ro

Nr

MT

1077

~ , 319 305 MT #n

303

Re

Figure 5 - Technique of overlaying soils on U.M.A. base map U.M.A. base map shows extent and number of each unique map area. clear overlay with soils (Ro) composite shows soils in the U.M.A.

17

4. LAND SUITABILITY FOR GROWING SUGAR CANE

4.1 The classification scheme

A land suitability classification is used to evaluate the potential

of land for the long term production of sugar cane. It simplifies the complex resource data into a more usable form for non-technical

users and provides a comprehensive overview of the total productive potential and associated problems of the study area.

The scheme was previously developed for the Rocky Point (Holz

1979), Moreton (Capelin 1979) and Mary River - Tinana Creek (Smith in

preparation) cane growing areas. It contains five classes which

represent increasing limitations to long term sugar cane production:

Class 1 - Land suitable with no limitations.

Class 2 - Land suitable with slight limitations.

Class 3 - Land suitable with moderate limitations.

Class 4 - Land marginally suitable with severe limitations.

Class 5 - Unsuitable land.

Land considered marginally suitable is particularly sensitive to

the economics of the industry when compared with suitable land. It requires high capital inputs to become suitable for growing sugar cane in the long term and is often the first to be taken out of production in depressed economic periods.

Land is placed into one of the five classes after considering any relevant limitations to production. Climatic limitations were not recorded for each uma because of the difficulty of transposing the diffuse boundaries of climatic changes on the uma boundaries.

Apart from climate, nine limitations to production were identified as being significant in the Mackay district:

18

moisture availability - m

soil nutrient - n

salinity and sodicity - s

topography - t

soil workability - k

stoniness - r

wetness - w

erosion - e

flooding - f

These limitations affect cane production through influences on

crop growth, cultivation and harvesting operations and land degradation.

The severity of each limitation is denoted by a subscript 1 to 5

corresponding to the five suitability classes. For example, m 3 n 2 denotes moderate moisture availability and slight soil nutriens limitations to production.

4.2 Limitations to Cane Production

Climate

Climate is a dominant limitation. The suitability of any area for

growing a particular crop depends primarily upon the area's climate and whether the crop can grow in that climate. Once it is determined that climate is suitable then other land factors which affect crop growth can be considered.

If the climate varies over an area then the suitability for crop growth may also vary. However, it is difficult to compare climate

between areas due to the shortage of recording stations. Thus, due to the lack of data and the problems of mapping climatic boundaries at the 1 : i00 000 scale, the use of the climatic limitation has been restricted to the following general discussion.

Most of the study area receives adequate rainfall for growing sugar

cane, however some areas receive significantly less. Significant deficiencies in rainfall have been demonstrated in the Eton area in

at least 50 per cent of years and serious deficiencies on an average of once in three years (Queensland Department of Primary Industries

and Irrigation and Water Supply Commission, 1975). Similar rainshadows

probably occur at Pinevale and in the headwaters of the Pioneer River.

Supplementary irrigation is probably required in these areas to attain equivalent production to other areas.

19

Bieske (1967), Ham (1969) and Kingston and Ham (1975) have illustrated the dependance of cane stalk elongation on mean daily temperature. Bieske (1967) showed that growth rates increased rapidly once mean daily temperature exceeded approximately 21~ whereas Ham (1969) and Kingston and Ham (1975) reported very rapid

�9 O increased stalk elongatlon rates once temperature exceeded 24 C. Using a critical temperature of 21~ and mean monthly temperature data, White (1970) calculated the growing season at Mackay to be seven months, between September and April.

Low temperatures also affect cane growth through the action of frost on growing points, stalks and leaves. The BSES experiment station at Te Kowai experiences an average of five frosts per annum (BSES data) but the alluvial flats around Gargett, Pinnacle and Eton have a much higher frost frequency (Pembroke 1982). In very severe winters frosts can occur in any low-lying pockets. Severely frosted mature cane must be harvested urgently before rain falls causing deterioration, however such frosting has been experienced in only four years since 1961 (Pembroke 1982).

Hail and strong winds can affect the production of sugar cane. Intense hail can cause severe damage, especially to young cane but occurs only very infrequently in the Mackay area. Strong winds burn cane leaves and can cause large cane to lodge if the ground is waterlogged.

Moisture avai labi l i ty

Water is an essential requirement for crop growth. The moisture regime of a crop is determined initially by the climate of the region which dictates water input through rainfall and also determines crop requirements through evaporation, temperature and radiation. The soil modifies these patterns by storing and subsequently releasing water to the crop as required. The proportion of stored water which is available to the plant is termed the available soil water capacity

(ASWC).

As the available soil water is depleted the soil moisture tension increases. Kingston (1972) found that sugar cane yields are adversely affected as the soil moisture tension in a Krasnozem soil approaches 4 bars at 230 mm depth, though the cane plant can tolerate soil moisture depletion up to this point. Robinson (1963) showed a reduction in cane stalk elongation with increasing soil moisture tension, which he considered was not recoverable at tensions greater than 2 bars, measured at 300 mm depth. Growth rate losses due to tensions less than 2 bars can be compensated for by increased growth rates following

re-wetting.

20

Kingston and Ham (1975) also report a very rapid decrease in stalk elongation rate until a soil moisture tension corresponding to 2.5 bars at 300 mm is approached. Thereafter the growth rate declines more slowly. They report a similar response for crop evapotranspiration.

Some growth restriction and decrease in cane yield may be expected between 2.5 bars and 4 bars tension but this can be compensated by higher ccs (Kingston and Chapman 1975). The critical soil moisture tension of approximately 4 bars at 230 mm, or mean tension of 1.6 bars over a 1 200 mm root zone, may be applied to soil types other than Krasnozems provided information on crop root depth and ASWC are obtained. Soils differ with respect to their ASWC through such parameters as infiltration rate, permeability, texture, depth, stoniness and salinity.

In irrigation experiments at Te Kowai on a soil considered to have moderate ASWC, Kingston and Chapman (1975) found that in some years irrigation would not be needed. However, the results did show that irrigation during the dry spring months was of most value in establish- ing the cane stool prior to the commencement of the wet season. The mean yield responses over i0 harvests at Mackay were 6.8 and 9.6 tonnes cane/ ha and 0.85 and 1.34 tonnes suger/ha for annual effective irrigations of 143 and 245 mm respectively (Chapman and Chardon 1979).

A water balance over a fourteen year period indicated that the drier Eton area has greater irrigation requirements compared with those for Mackay (Chapman and Chardon 1979). These results also indicated that soils with low ASWC required more frequent lighter irrigations than those with higher capacities but there was not a great deal of difference in the total amount of water required.

While a water balance model can indicate that one centre has a different crop water regime from another, there are not sufficient centres with adequate data in the study area to map the geographical boundaries between different regimes. As a result, the soils in those areas perceived as being drier due to lower rainfall were not given a greater moisture availability limitation than others. It is anticipated that these drier areas are located at Eton, Pinevale and in the head-waters of the Pioneer River. The moisture regime at Mentmore, compared with the remaining study area, is unknown.

Relevant soil parameters were used to assess the moisture availability of each soil identified in the study area and allot a limitation where appropriate. The Pioneer soil with moderate ASWC was used as a benchmark and was considered to have no significant moisture

availability limitation.

21

Soil Nutrients

Virtually all of the nutrients required for cane growth are removed in the crop at harvest and must be replaced for production of the next crop (Chapman 1977). Moreover, sugar cane is a high yielding crop with a large demand for the supply of nutrients. Chapman (1977) in discussing the nutrient requirements and fertilizer responses of cane shows that an 85 t/ha crop grown at Mackay removes I00 kg/ha of nitrogen, 25 kg/ha of phosphorus and 200 kg/ha of potassium. He points out that the objectives in fertilizing cane are to fill the gaps between the level of nutrients in the soil and the level necessary for optimum growth.

In the Mackay district, applications of nitrogen, phosphorus and potassium are accepted as a standard farming practice, a practice supported by experimental data (Chapman 1977, 1980, 1982). Recommended rates of fertilizer depend upon such variables as crop class (plant or ratoon), potential crop yield, soil type, irrigation and finally sugar price, i.e., return per unit of fertilizer.

The high yields resulting from these large fertilizer inputs may lead to a deficiency of other nutrients not normally applied in fertilizer.

This effect is most significant in soils with low inherent fertility, which are generally those having deep, coarse textured A horizons, acid pH and low cation exchange capacity (CEC). Yield responses to calcium, and deficiency symptoms of copper have been noted in these soils (Chapman 1977).

Inefficient use of fertilizers may be a problem on some soils. Chapman (1977) has estimated losses of nitrogen fertilizer on a coarse textured soil at Mackay to be as high as 88% and suspects sulphur deficiency may be emerging on some of these soils. These losses are probably due to excessive leaching of the soil profile.

As the application of nitrogen, phosphorus and potassium is required on all soils, a soil nutrient limitation has only been given to those soils either requiring applications of other nutrients or with excessive leaching losses of nitrogen, and possibly sulphur.

Salinity and Sodicity

Plant growth is restricted by an excess of soluble salts in the soil water (salinity) and by excess sodium on the soil CEC (sodicity). Sodicity may also affect soil workability by causing soils to remain wet for long periods following rain and to become tough and intractable when dry. Salinity and sodicity may occur either independantly or simultaneously.

22

Ridge (pars. comm.) has established the relationships between

restriction of cane growth and salinity (as measured by electrical conductivity). The results, shown in Table 6, are used by the BSES for assessing salinity in Queensland's cane growing areas.

Table 6. Salinity standards for soils in the Queensland canegrowing areas

Soil texture Degree of growth restriction

None Slight Moderate Severe

i. 1 : 5 soil water suspension (electrical

conductivity, mS/cm)

Organic <0.32 0.32 - 0.65 0.65 - 0.97 >0.97

Clay <0.28 0.28 - 0.55 0.55 - 0.83 >0.83

Clay loam <0.21 0.21 - 0.42 0.42 - 0.62 >0.62

Loam <0.19 0.19 - 0.39 0.39 - 0.58 >0.58

Sandy loam <0.19 0.19 - 0.37 0.37 - 0.55 >0.55

Sand <0.14 0.14 - 0.28 0.28 - 0.42 >0.42

2. Saturation extract (electrical conductivity, mS/cm)

2.0 2.0 - 4.0 4.0 - 6.0 6.0

Vega (1977) examined the effect of sodicity on sugar cane yields.

There was no significant yield reduction while the percentage of exchangeable sodium (ESP) on the soil CEC was less than i0. Yields

were reduced by 15% for an ESP of 15%, by 50% for an ESP of 25 to 26% and there was virtually no production for an ESP of 45%. The BSES

also consider cane production to be affected when the ESP reaches 15% in soil samples taken within 500 mm of the surface (Haysom pars. comm.).

Salinity and sodicity need not be inherent soil features.

Secondary salinity and sodicity can occur as a consequence of agricultural practices, irrigation, or clearing of the native vegetation (Northcote and Skene 1972). In the Mackay area secondary occurrences are mainly associated with seepage areas but also with

the intrusion of ground-water tables by sea water (Ham and Chapman

1982). It is difficult to predict the location of outbreaks as even soils without saline or sodic properties may develop secondary

23

salinity or sodicity from external sources. There are, however, some relationships between geology and landform from which broad, susceptible areas can be identified.

The saline areas associated with sea water intrusion may result from excessive irrigation from shallow aquifers close to the coast or following clearing and cultivation of land adjacent to mangroves and saltmarsh. Sea water intrusion tends to affect areas of several hectares in size.

Occurrences of secondary salting from seepages are generally less than one hectare in size. However, their impact is magnified because their extreme workability problems create difficulties in working entire blocks. There is probably also a much larger area which suffers only a slight reduction in crop growth and so goes undetected.

A salinity and sodicity limitation has been given to any uma's which contain a significant proportion of secondary salinity and/or sodicity. The degree of limitation (s^, s~, sA) depends upon the number and size of these areas wlthln ~he uma.

Topography

Topography affects the use of machinery for cultivation and harvesting operations. The large machinery used in sugar cane production is most efficient when operated on extensive areas of level ground or gentle, planar slopes.

Undulating land with its crests, uneven slopes and associated gullies is less suitable for the use of machinery. As the land becomes more undulating, crests and slopes become steeper and more complex, gullies become narrower and more frequent, and the suitable areas become smaller, more fragmented and less accessible.

A topographic limitation exists wherever gully dissection and/or steep, complex slopes and crests significantly increase the difficulty

of cultivation and harvesting.

Soil workability

A soil workability limitation has been given to soils with properties which limit the timeliness of cultural operations, the choice of implements or which require more cultivations to achieve the desired

result.

Soil properties which affect the use of machinery include heavy clays, stiff clays, hardpans and compacted layers within the depth of cultivation, and surface soils which are pulverescent when dry and 'spewy' when wet. Many of these soils can only be cultivated over a

narrow moisture range.

24

The heavy clays, stiff clays, hardpans and compacted layers require

more powerful tractors, heavier machinery and usually more cultivations at a higher cost to achieve the same result as for other soils. Surface soils which are spewy when wet and/or hard and pulverescent when dry restrict the time period available for cultivation.

Optimum crop performance depends upon the timeliness of cultivation for land preparation, planting and weed control. It is desirable that a soil can be cultivated over a wide range of moisture levels to give some flexibility to the timing of these operations. Soils with a narrow moisture range dry rapidly leaving only a relatively short period over which these operations can be carried out (Holz 1979).

Stoniness

Loose stones and rock outcrop interfere with cultivation and harvesting operations. Machinery can sustain substantial damage from stones. Harvesting operators estimate that some stony areas may take twice as long to harvest as stone-free areas (Anon 1981). Stony areas result in less efficient harvesting because basecutters are set high to miss "floaters". Areas with excessive stone and rock outcrop must be excluded from cultivation or be cleared of stone prior to use.

All stone, whether large or small, decreases moisture availability to the crop by decreasing the volume of soil available to store water. This feature has been considered as part of the moisture availability

limitation.

In the Mackay area, the loose stone associated with fine grained sedimentary rocks tends to be small, angular and brittle. Rock bars of the sedimentary beds more resistant to weathering outcrop on the surface. Coarse grained sediments of quartzose sandstone outcrop on the surface and associated stone is usually large. Acid to intermediate volcanic stone is generally angular and smaller than the larger, rounded stone of the intermediate to basic volcanics. There is little stone associated with the acid to intermediate intrusives except for

that shed from dykes.

Wetness

The wetness limitation takes into account the adverse effects of excess water on cane production through the reduction in crop growth and quality, restrictions on the use of machinery following rain, costs of drain construction and maintenance, and costs of land reclamation (Holz 1979).

25

Wetness refers to excess water on the soil surface and in the

profile as a direct result of rainfall or run-on from adjacent land. The excess water can occur due to poor soil permeability, high water-

tables and inadequate surface disposal systems. This is in contrast with flooding which, in this report, refers to excess water as a direct result of stream channel overflow.

Cane grows most successfully with a high rainfall on a freely drained soil. Though reasonably tolerant of waterlogged conditions, a cane crop may suffer complete cessation of growth due to anaerobic soil conditions. Reduction in tillering, reduced ccs, increased susceptibility to disease, scalding from high water temperatures and death may also occur. The severity of damage depends upon the age and maturity of the crop and the duration of waterlogging. Young cane is particularly susceptible to inundation and death may result if water (particularly silt-laden) covers the growing point for more than a few days.

High water-tables have been shown to seriously reduce cane yields. Gosnell (1971) grew cane with water-tables held at 250, 500, 750, 1 000 and 1 250 mm. He found growth inhibited with the 250 and 500 mm treatments, no differences between the 750, 1 000 and 1 250 mm treatments but recommended the water-table be maintained below 1 000 mm. In a similar investigation Juang and Uehara (1971) found that cane yielded best with a water-table maintained at 800 mm depth compared with 300 and 500 mm depths.

Maclean (1977) measured yield difference due to poor drainage of up to 30 tonnes cane/ha in the same paddock in the Goondi mill area. Yields were reduced significantly when the water-table was within 600 mm of the soil surface. Rudd and Chardon (1977) investigated yield losses resulting from high water-tables in the Macknade mill area. Mean losses of 30 t cane/ha were measured between adequately and inadequately drained sites. They considered freely drained soil to at least 500 mm depth was necessary to improve yields. McIntosh (1977) has demonstrated some benefits of well-planned drainage on farms in the Victoria mill area including substantial monetary gains due to increased crop yields from even small areas of drained land.

Paddocks which remain wet also prevent cultivation and harvesting operations from being executed at the otpimum time. Machinery operations in wet conditions, particularly during harvesting, can involve increased costs and have adverse agronomic effects. Soil compaction can occur when the moisture content is below the plastic limit, the highest moisture content at which the soil can be cultivated without puddling (Maclean 1976). In very wet conditions, soil puddling can occur forming an anaerobic soil environment (Fuelling 1979). Cane yields of ratoon crops may be adversely affected by both

conditions.

26

Drainage measures for sugar cane lands have been described by Lowndes (1957, 1965). The measures aim to rapidly remove surface water and to lower water-tables. Surface drainage techniques include land levelling, bedding, water furrows, cross drains and main drains while subsurface drainage includes deep farm drains, mole drains and pipe and tile drains. The benefits are reduced if there is no effective disposal system provided from the farm boundary.

Erosion

Sloping land is susceptible to soil erosion by water. Pink (1975) reports that after 1945 significant areas of steeply sloping land in Queensland became so badly eroded that they had to be abandoned for sugar cane production.

The factors affecting soil erosion are rainfall, soil erodibility, topography, cropping or management practices and erosion control practices.

Sallaway (1979) found that soil losses generally increased as the land slope increased in Mackay canelands but this effect appeared to be strongly modified by soil type. Late cultivations for weed control into the summer storm period greatly increased soil movement (Sallaway 1980). He assessed nett annual soil movement down cane blocks to be between 42 and 227 t/ha.

Soils losses should be reduced to the lowest levels possible, but in order to plan practicable soil conservation measures, a maximum loss of 12.5 t/ha/an is used (Rosser et al 1974). Integrated soil conservation works include diversion banks, parallel contour banks and waterways. Management options include trash retention and reducing late cultivation.

Following discussions with officers of Soil Conservation Services Branch of the Department of Primary Industries, the Mackay soils were placed into four soil erodibility groups based primarily upon local experience (see Table 7). The soils of the high erodibility group have coarse textured, non-coherent surface soils. The moderate group are duplex soils with hardsetting, medium textured surface soils and less permeable clay subsoils. Medium to fine surface textures with weak to moderate structure overlying permeable subsoils are a feature of the moderate to low group whereas soils in the low group have fine to medium textured surface soils with stronger structure.

Table 7. Relative erodibility ratings for Mackay soils

Soil erodibility rating

High Moderate Moderate-Low Low

Dunwold

Farleigh

Gargett

Gargett, deep A horizon variant

Kuttabul

Kuttabul, alluvial- colluvial variant

Marwood

Mentmore, sandy loam variant

Mulei

Munbura

Septimus

Tannalo

Uruba, sandy A horizon variant

Belmunda

Jumper

Mentmore

Ossa

Ossa, cobbly variant

Palmyra

Pindi

Seaforth

Whiptail

Wollingford

Wollingford, intrusive parent material variant

Wollingford, yellow B horizon variant

Etowrie, neutral- duplex variant

Habana

Kowari

Martin

Netherdale

Uruba

Uruba, alluvial- colluvial variant

Etowrie

Finch Hatton

Finch Hatton, alluvial- colluvial variant

Glenella

Kungurri

Nabilla

Pinnacle

Royston

Silent Grove

Wagoora

Wagoora, basic parent material variant

28

An upper slope limit for cultivation was determined for each group. The limit represents the maximum slope on which cultivated land can be adequately protected against soil erosion. The experience in the Childers district was that all the cultivated land above 12% slope was rapidly degrading and much had become unproductive (Isis Land Use Study Con~nittee 1971). Of the land between 8 to 12% slope some was degraded and unproductive and some was stable and productive if protected by soil conservation measures. The lower limit below which soil erosion was not significant was accepted as 2% slope (Soil Conservation Services Branch pets. comm.).

When assessing the severity of the soil erosion limitation for each uma, the slope percentage, complexity of slopes, soil erodibility rating of the soil and ability to plan effective soil conservation layouts have been considered.

Flooding

Lands periodically inundated by water from stream channel overflow have a flooding limitation. An evaluation of severe flooding in the Mulgrave and Babinda areas in 1977 showed the major variables influencing yield losses of cane were length of the stalk at flooding, time of complete submergence of the growing point, the variety of cane and characteristics of the water such as silt content and strength of the current (BSES 1977).

The critical stalk length was found to be approximately one metre. Stalks less than 1 m high suffered greater damage for a particular time of submergence. The degree of flood tolerance showed a marked varietal effect. Varieties with some flood resistance will tolerate complete submergence for up to 3 to 4 days but losses escalate to 30 to 40% if submerged for 5 to i0 days and 60 to 70% for ii to 19 days. The proportion of growing points killed increased with the quantity of silt deposited. This problem can be particularly acute in backwaters where there is less current. Yield losses can also result from strong

currents breaking cane stalks.

Fast flowing floodwaters can also erode stream banks, strip valuable topsoil from one location and dump sand and mud together with extraneous objects such as rocks and logs in others. Stream bank erosion reduces the area of cultivation while extraneous objects present serious hazards to machinery operation.

Flooding is a limitation on the terraces flanking the major streams of the study area. Repeated, severe flooding has caused cane assignments to be transferred from susceptible areas such as Cameron's

Pocket.

29

It is difficult to assess the flooding limitation for each uma due to a lack of information about flood frequency and severity for any particular affected area. Thus the severity of the flooding limitation was mainly assessed using information collected from farmers and extrapolating on the basis of soils.

4.3 Suitability of unique map areas and soil mapping units

The section outlines the rationale behind the limitations given to each uma and each soil mapping unit. The areas, major limitations and soils in each suitability class are given in Table 8. The location of all Class 1 to Class 5 land is shown on Map 2.

The limitations identified for any uma can be attributed to soil characteristics, landform or a combination of the two. Moisture availability, soil nutrient, soil workability and stoniness are largely soil-related limitations. Topography and flooding limitations are landform-related. Wetness, erosion and salinity limitations are the result of both landform and soil characteristics. There is usually a strong correlation between landform and soils and hence limitations, e.g., Murray soils occur in a landform position where they are frequently flooded and Finch Hatton soils often occur on steep slopes with a moderate to severe erosion limitation.

Soils of uplands derived from acid crystalline ruffs

The Marwood soil is Class 3 and has moisture availability (m^), soil nutrient (n_) and wetness (w 3) limitations. The deep coarseJtextured surface soils have a low ASWC. The soil nutrient problems include low CEC, low calcium and copper levels and possibly high nitrogen fertilizer losses from leaching. Water remains perched on the subsoil for long periods after rain.

The Munbura soil is Class 3 and has moisture availability (m 3) and erosion (e 2 ~) limitations. The coarse textured profile has low -j ASWC. This soil is highly erodible and occurs on undulating rises with slopes commonly of 2 to 6%. Low CEC and low calcium levels are also a feature of this soil but it was not considered a significant soil nutrient limitation.

Soils of uplands derived from acid to intermediate intrusives and dykes

Dunwold soil is mostly Class 3 with a small area of Class 4. It has moisture availability (m~), soil nutrient (n~), wetness (w 2) and

J z erosion (e 2 4 ) limitations. The deep, coarse textured surface soil has a low ASWC. The soil nutrient limitation is due to low CEC and calcium levels and possible high nitrogen fertilizer losses from

leaching. Seepages are a common feature, hence the wetness limitation. This soil is highly erodible and occurs on undulating rises with slopes commonly 4 to 6%. Some occurrences on steep, uneven slopes have a

topography limitation (t2_3).

30

The Septimus soil is Class 3 and has moisture availability (m3) , soil nutrient (n^) and erosion limitations (e~). It is closely

J associated with ~unwold soil. The moisture availability and soil nutrient limitations are due to coarse textures with low ASWC, low CEC and low calcium levels. This soil is highly erodible and occurs on undulating lands.

The Uruba, sandy A horizon variant is Class 4 and has moisture availability (m 3) , erosion (e~ ~), stoniness (r_ .) and topographic j-q -j (t~) limitations. The coarse textured profile ~as low ASWC This j soll is highly erodible and occurs on steep, uneven slopes of commonly 6 to 12%. Rock outcrops on steeper slopes.

The Gargett soil is Class 3 and has moisture availability (m~), wetness (w 2) and erosion (e^ ~) limitations. The deep coarse texJtured z-J surface soll results in a low ASWC. Seepages commonly occur in this soil, it is highly erodible and occurs on gently undulating to undulating land with slopes commonly 1 to 4%.

The Gargett deep A horizon variant is Class 3 and has moisture availability (m.), soil nutrient (n^) and wetness (w~) limitations. It has a similar moisture availabillty limitation (m) to the Gargett soil but the coarse textured surface soil is deeper. Water remains perched on the impermeable clay subsoil for long periods and seepages

also occur. Low CEC and probable nitrogen leaching losses result in a nutrient limitation. Natural gullies formed in this soil on the long alluvial-colluvial slopes have been mapped as Gullied Lands.

The Tannalo soil is Class 3 and has a moisture availability limitation (m 3) due to the low ASWC of the coarse textured surface soil. This soil is highly erodible, mostly occurs on low slopes of 2 to 4% and has an erosion limitation (e 2 ~). A stoniness limitation (r^) due to rounded cobble occurs infrequently as does a topography limitation (t 2) due to gullies.

Finch Hatton soil is Class 3 and Class 4 due to erosion (e~ j) and occasional stoniness (r^ 4) and topography (t^ ~) limitations. J-~his soil has a low soil ero~[~ility but occurs onZs~eep slopes of 6 to 12%. Consequently, it has a moderate to severe erosion limitation. A topography limitation is associated with uneven slopes and gullies. There may also be a stoniness limitation due to tors of granodiorite or due to rounded cobble from the many dykes which occur in the geological formation.

The Netherdale soil is Class 3 and Class 4 and has moisture availability (m2), topography (t^ 4) and erosion (e~ .) limitations. z-~ J-~ The surface soil overlies decomposing granodiorite which becomes coarser textured and so has lower ASWC with depth. This soil has a low to moderate soil erodibility rating. It occurs on the crests of ridges with steep slopes of 6 to 12% resulting in the topography and erosion limitations.

31

Uruba soil is Class 2, Class 3 and Class 4 and has moisture

availability (m2), stoniness (r 2 ) and erosion (e^ j) limitations -3 z-4 "

The duplex profile has a low to medium ASWC. This soil occurs on undulating rises of commonly 4 to 10% and has low to moderate soil erodibility. The stoniness limitation is due to gravel and cobble shed from dykes. Uma's with uneven slopes and gullies have a topography limitation (t 3) .

Pinnacle soil is Class 2 and has only an erosion (e 2) limitation. It has low soil erodibility and occurs on undulating rlses of 4 to 6%.

Farleigh soil is Class 3 and has moisture availability (m 3) and erosion (e^ .) limitations. It has coarse textured surface soil

z- overlying often only a narrow band of clay subsoil then coarser textured decomposing granodiorite. Thus the profile has a low ASWC. This soil is highly erodible and occurs on undulating rises with mostly gentle slopes of around 4%.

Kowari soil is Class 3 and Class 4 with a moisture availability limitation (m~) due to the abundance of stones in the profile and a

stoniness limitation (r_ 4 ) due to colluvlal rounded basic volcanlc 3-- l cobble and stones. Some uma s have an erosion limitation (e2).

The Finch Hatton alluvial-colluvial variant is Class 1 with no limitations and Class 2 with a slight erosion limitation (e2). This soil has low erodibility and occurs on slopes of 2 to 4%.

The Uruba alluvial-colluvial variant is Class 2, Class 3 and Class 4 with moisture availability (m~), erosion (e^ ~) and topography (t 2 3 )

~-~ 0 limitations. The moisture availability limitation is due to the duplex profile with low to medium ASWC. This soil has low to moderate soil erodibility and occurs on slopes commonly of 2 to 4%, though some uma's have steeper slopes and dissected topography.

Soils of uplands derived from basic to intermediate volcanics

The Wagoora soil is Class 2, Class 3 and Class 4, the Wagoora basic parent material variant is Class 2, Class 3 and Class 4 and the

Royston soil is Class 2 and Class 3. These soils have erosion (e2_ 4) , stoniness (r^ ~) and topography (t^ .) limitations. They have low z-J erodibility ~u~ occur on slopes commonly of 2 to 8%. The stoniness limitation is due to rounded intermediate to basic volcanic cobble

and stones and some rock outcrop.

The Nabilla soil is Class 2, Class 3 and Class 4 and has moisture availability (m), erosion (e _) and stoniness (r^ 4 ) limitations.

2-J This soil has a~undant iron-manganese nodules which-reduce the ASWC and is often shallow to only moderately deep. A stoniness limitation results from mainly rock outcrop and some rounded intermediate

volcanic cobble and stone. The soil erodibility is low but this soil occurs on slopes of 2 to 6%. Some steep uneven slopes adjacent to

Mt Vince have a topography limitation (t3).

32

The Martin soil is Class 2, Class 3 and Class 4, while Habana soil is Class 3 and Class 4. Both these soils have moisture availability (m~), stoniness (r^ ~) and erosion (e~ ~) limitations. The shallow profiles and abundance of angular stone through the profiles give both these soils low ASWC. Soil erodibility for both soils is low to moderate but these soils commonly occur on slopes of 4 to 10%. A topography limitation (t2_ 3) has been given to some uma's with steep uneven slopes.

The Kungurri soil is Class 3 with soil workability (k_), erosion i (e 3) and stoniness (r 2) limitations. Farmer experience indicates that thls soil has a narrow moisture range for working and is 'tough' to cultivate when dry. Intermediate volcanic gravel and cobble may occur. This soil has low soil erodibility but occurs on slopes of commonly 3 to 6%.

Glenella soil is Class 2, Class 3 and Class 4 due to erosion (e2_ 4) and stoniness (r 2 ~) limitations. It has low soil erodibility but occurs on slopes o~ 2 to 10%. Rock outcrop and the quantity of rounded intermediate volcanic stone and cobble is variable.

Silent Grove soil is Class 2, Class 3 and Class 4. Etowrie soil is Class 2 and Class 3. Both soils have a soil workability limitation (k 2) due to clay surface soils with a narrow moisture range for working. Wetness (w~) and erosion (e^ 4) limitations depend on landform.

z z-J These soils have low soil erodibility and commonly occur on very gentle slopes of 1 to 4%. A soil erosion limitation has been given to uma's with slopes over 2%. A wetness limitation has been given to those uma's where external drainage is poor. One uma of Silent Grove soil has a stoniness (r 4) limitation.

The Etowrie neutral duplex variant is Class 2 and Class 3. It has moisture availability (m~), stoniness (r^), wetness (w^) and

is assumed to have low erosion (e 2 4) limitations. -The duplex profZlle z to moderate-~SWC. Rounded intermediate volcanic cobble and stone may occur. This soil has a low to moderate soil erodibility and occurs on slopes of 1 to 4%. A soil erosion limitation has been given to uma's over 2% slope.

Soils of uplands derived from aaid to intermediate volcanics

The Whiptail, Wollingford, Wollingford intrusive parent material variant, Wollingford yellow B horizon variant and Mentmore soils have duplex profiles with moisture availability (m 2 3 ) , stoniness (r 2 ),

Cs~ ~) erosion (e 2 4 ) and occasional topography (t 2 4[ and salinity -4 limitations? Together these soils comprise 20 ha of Class 2, i~-~50 ha of Class 3 land and 1 130 ha of Class 4 land. The often shallow duplex profiles have impermeable subsoils and low ASWC. Rock outcrop and mostly angular acid volcanic gravel and cobble are a common feature of these soils. They have moderate soil erodibility and occur on slopes

33

ranging from 2 to 8%. These soils are especially susceptible to soil erosion because the relatively shallow surface soils overlie sodic clay subsoils. Secondary salting/sodicity is associated with these soils and consequently some areas have been downgraded. A topography limitation has been given to some uma's with uneven dissected slopes and gullies.

The Mentmore sandy loam variant is Class 4 due to a severe moisture availability limitation (m.) as well as stoniness (r_) and

J erosion (e 2 4) limitations. The coarse textured shallow surface soil overlies an-fmpermeable clay subsoil and has a very low ASWC. This soil is highly erodible and occurs on slopes of 2 to 6%.

The Belmunda soil is Class 3 and Class 4 due to moisture availability (mr), erosion (e^ _) and stoniness (r^ 4 ) limitations. The soil profil~ z-~ ~- has abundant iron-manganese nodules which reduce the ASWC. This soil has moderate soil erodibility and occurs on slopes

of 3 to 6%. Rock outcrop and cobble, stone and occasionally boulders of intermediate volcanics occur. A uma near St. Helens composed of Belmunda and Skeletal soils and Frontal Dunes has been mapped as unsuitable for cane growing because of rock outcrop and the long narrow shape is not suited to farm layout.

Soils of uplands derived from sedimentary rocks

The Pindi and Jumper soils are Class 3 and Class 4 and have moisture availability (m.), stoniness (r 2 ~), erosion (e^ .) and salinity (s^ ~) limitations. T~e low ASWC of bo~ ~-~ z-J these soils is due to the often shallow duplex profiles with relatively impermeable subsoils and the abundance of iron-stained gravel in the surface. The stoniness limitation is usually due to angular sedimentary (mudstone, siltstone) gravel and outcrops of the more resistant sedimentary beds also occur. These soils are moderately erodible and occur on slopes of commonly 2 to 6%. Secondary salinity/sodicity develops occasionally in lower slope positions.

The Palmyra soil is Class 4 with moisture availability (m 4) , stoniness (r_) and erosion (e^ ~) limitations. It is associas with

5 and similar ~o the Jumper and Pzndi soils but is shallow and gravelly through the profile. There is abundant angular sedimentary stone and rock bars are common. It has a moderate soil erodibility and occurs

on slopes of 4 to 8%.

The Kuttabul soil is Class 3 and Class 4 due to moisture

availability (m3), stoniness (r~ ~) and erosion (e 2 ~) limitations. The coarse textured surface soi~-~nd mottled clay subsoil has a low ASWC. The stoniness limitation is due to rock outcrop of sandstone with surface cobble and stone. This soil is highly erodible due to the high proportion of fine sand in the surface soil and occurs on

slopes commonly of 3 to 6%.

34

The Mulei soil is Class 3 and also developed on sandstone. In addition to the moisture availability (mr) and erosion (e^ 4) limitations this soil has a soil nutrien~ limitation (n2)Zdde to a low CEC, low calcium levels and probable leaching of nitrogen fertilizers.

Soils of alluvial-colluvial plains derived from sedimentary rocks and acid to intermediate volcanics

The Ossa, Seaforth, Seaforth yellow B horizon variant and Balberra are Class 3 soils due to moisture availability (m~), wetness (w _),

2- erosion (e^ 3 ) and occasionally stoniness (r^~ limitations. ~hese

z- z soils have low to moderate ASWC due to moderately deep, medium textured surface soils overlying mottled relatively impermeable clays. The wetness limitation is due to water remaining perched on the clay subsoils for long periods following rain and seepages commonly occur through the Ossa soil. The Balberra soil has a moderate wetness limitation (w) since it occurs on flat topography with limited surface drainage. Th~ Ossa soil occasionally occurs on slopes up to 4% and is moderatley erodible. Some erosion problems occur on long slopes of only 1 to 2%. There is occasionally subrounded cobble through these soils.

The Ossa cobbly variant is Class 3 and Class 4 due to moisture availability (m~), stoniness (r~ ~) and erosion (e~) limitations. The abundant rounded cobble is a feature of this soil. 5 The cobble reduces the ASWC as well as affecting machinery. This soil is moderately erodible and occurs on slopes of 2 to 6%.

The Seaforth dark B horizon variant is Class 2 due to a slight wetness limitation (w~) from impeded profile and surface drainage but probably has a moderate to high ASWC due to a fine textured surface.

The Kuttabul alluvial-colluvial variant is Class 3 with a moisture availability (m~) limitation due to the low ASWC of the coarse textured surfac~ soil. The surface soil is highly erodible and together with long slopes of commonly only 1 to 2% results in a slight

erosion limitation (e2).

Soils derived from Quaternary alluvium - duplex soils of the alluvial plains

The Calen, Sandiford, Marian and Marian yellow B horizon variant soils are mostly Class 2 soils with moisture availability (m^) and wetness (w 2) limitations. These soils remain waterlogged afte~ rain because they occur on flat topography with limited surface drainage and they have impeded profile drainage through the clay subsoils. On drying, they have only low ASWC. Some Marian uma's have profiles with permeable subsoils and have no limitations to cane growing. Some uma's of Calen and Sandiford soils have been downgraded due to secondary salting/sodicity (s 2 4 ) . Some Calen uma's have been downgraded to Class 3 and Class 4 due to topography (t 3) and wetness (w 4) limitations.

35

Eton and Narpi soils are mostly Class 2 and have a slight wetness limitation (w 2) due to impeded profile drainage and flat topography. They have no moisture availability limitation due to the high ASWC of the fine textured surface soils. Gullied Lands are a feature of the alluvial plains of Narpi soil and some uma's have been downgraded due to a topography limitation (t^ 4). Some secondary salinity has -j developed in these soils due ~o high water tables (s3_4).

Sunnyside soil is Class 3 due to moisture availability (m2) , soil workability (k) and wetness (w^) limitations. The moisture limitation

2 5 is due to a shallow silty surface soil overlying relatively impermeable clay with probable poor root penetration. The flat topography and impeded profile drainage result in a wetness limitation. The silty, bleached, hardsetting surface soil and shallow depth to the clay subsoil makes this soil difficult to cultivate outside a narrow moisture range.

The Mirani soil is Class 3 and has a moderate moisture availability limitation (m~) due to the deep coarse textured surface soil. Some uma's with fl~t topography have a slight wetness (w 2) limitation.

Uniform clay soils of the alluvial plains

Victoria Plains and Brightley soils are mostly Class 2 due to slight wetness (w^) and workability (k 2) limitations. They have impeded

z profile drainage and occur on flat topography with poor surface drainage. After wetting, they have only a narrow moisture range over which they can be cultivated before becoming dry, hard and intractable. Some uma's of both Victoria Plains and Brightley soils have been downgraded due to secondary salinity/sodicity (s2_ 4) or very poor surface drainage

(w3).

The Benholme and Dundula soils are Class 3 due to soil workability (k^) and wetness (w~) limitations. These soils have tough, stiff, relatively imperme~le clays on flat topography and the combination of wetness and soil workability downgrades them to Class 3. The Dundula

soil is affected by salinity/sodicity (s2_4).

Duplex soils of the relict plains

The Kinchant soil is Class 4 due to moisture availability (m4), soil nutrient (n_), salinity (s~) and wetness (w~) limitations. This soil

J J & has a deep coarse textured surface with very low ASWC. The soil nutrient limitation is due to low CEC, low calcium and copper levels and probable nutrient leaching. The wetness limitation is due to the long periods following rain when the surface soil remains waterlogged. The subsoil is sodic and the Allandale strongly sodic variant is usually associated so the Kinchant uma's were given a salinity limitation.

36

The Kinchant coarse sandy variant is Class 3 due to moisture availability (mr), soil nutrient (n 3) and wetness (w~) limitations.

J While this soil has similar profile features to the ~inchant soil, it is non-sodic and therefore was considered to have a higher moisture availability. There is not the extent of associated sodic soils so a salinity limitation was not given.

The Allandale soil is Class 3 with moisture availability (m3), wetness (w 2) and salinity (s~) limitations. The duplex profile has low ASWC and the relatively impermeable clay subsoil allows only poor root and water penetration. The salinity limitation of the uma's is due to the closely associated Allandale strongly sodic variant. The wetness limitation is due to impeded internal and surface drainage.

The Allandale strongly sodic variant is Class 5 and unsuitable for canegrowing. The shallow coarse textured surface soil overlies strongly alkaline, sodium saturated, clay subsoil and hence has a salinity limitation (s5). Some recent expansion onto this soil resulted in complete crop failure.

Soils of levees, terraces and floodplains

The Pioneer and Pioneer red B horizon variant soils have no limitations to canegrowing though some uma's with slopes around 4% suffer minor soil erosion.

The St. Helens soil is Class i, Class 2 and Class 3. There are no soil properties which limit production but due to its development on river terraces and floodplains there are occasional flooding (f2_3) ,

stoniness (r2), erosion (e 2) and topography (t2_ 3) limitations.

Cameron soil is Class 2, Class 3 and Class 4 due to moisture availability (m~_~), flooding (f2_4) , topography (t~z_j4) and occasional stoniness (r^ _7 Iimitations. T~is soil has a uniform, medium textured pro~[~e which is underlain by layers of sand or gravel at varying depths. Therefore, the moisture availability may vary depending on the depth of medium textured soil. This soil is developed on floodplains and so is subject to flooding. It may have river gravels and cobble through the profile. Floodplains or terraces have often uneven and dissected slopes, hence the topography limitation.

Murray soil is Class 3 and Class 4. It occupies the lowest floodplains and suffers a flooding (f? 4 ) limitation. The uniform coarse textured profile has low ASWC Imp). A nutrient limitation (n 2)

, J has been given to those uma s with deep profiles which would suffer from leaching. Occasionally Murray soil overlies fine textured material at shallow depth and these uma's were not given a soil nutrient limitation. A stoniness limitation (r_ A) is due to river -4 gravel and cobble which occur commonly through ~hls soil. Some uma's

with a dissected floodplain have a topography limitation (t3).

37

Soils of the beach ridges and coastal dunes

The Andergrove, Andergrove coarse sandy variant and Andergrove calcareous variant soils have moisture availability (m3), soil nutrient (n^),z wetness (w.)~ and topography (t 3) limitations. Some uma's with long narrow ridges separated by swamps and adjacent to mangrove areas have been considered marginal or unsuitable for growing sugar cane. The moisture availability limitation is due to the low ASWC of the deep coarse textured profile. Potential leaching of fertilizers and low calcium levels (except for the Andergrove calcareous variant) have resulted in the soil nutrient limitation.

The Neils soil has a moisture availability limitation (mr) due to J

the low ASWC of the coarse textured surface of the duplex profile. Salt water intrusion from nearby mangroves and low topography have resulted in salinity (s 3) and wetness (w 3) limitations in one uma.

Miscellaneous Mapping Units

Mountains and Hills are unsuitable for canegrowing because of steep slopes, shallow stony soils and rock outcrop.

Unsuitable lowlands include Mangroves and Saltmarsh, Freshwater Swamps, Streambeds and Gullied Lands. Gullied Lands may occur in upland areas but all uma's have been included as lowlands on Map 2 and Map 3 Urban and Industrial land and Kinchant dam have been alienated from agricultural use. Skeletal soils including shallow gravelly, stony or cobbly soils and lithosols occur in some uma's but are not mapped separately.

38

Table 8.

Table 8a.

The areas, major limitations and soils in each suitability class

Mapping units of class 1

Soils* Major** Area

Limitations (ha)

Soils of uplands derived from acid to

intermediate intrusives and dykes;

- medium to fine surface textures

Finch Hatton, alluvial-colluvial variant

Soils derived from Quaternary alluvium:

- duplex soils of the alluvial plains

Marian

- soils of levees, terraces and floodplains

Pioneer

Pioneer, red B horizon variant

St. Helens

Nil 90

Nil 430

Nil 2 460

Nil 600

Nil 1 070

TOTAL 4 650

* Soils are those described in Part i, The Land Resource Inventory.

** The major limitations (particularly those landform related) are

not necessarily present in every uma.

39

Table 8b. Mapping units of class 2

Soils Major

Limitations

Area

(ha)


intermediate intrusives and dykes:

- coarse surface textures

Uruba

Uruba, alluvial-colluvial variant


Pinnacle

Finch Hatton, alluvial-colluvial variant

m 2 e 2

m 2 t 2

e 2

e 2

l0

330

120

340

Soils of uplands derived from basic to

intermediate volcanics:

Wagoora


Glenella

Royston

Martin

Nabilla

Silent Grove

Etowrie

Etowrie, neutral duplex variant

e 2

e 2

e 2

e 2

m 2 r 2 e 2

m 2

k 2 e 2

k 2

m 2 r 2 w 2

890

540

300

60

30

1 250

2 080

1 100

140



Wollingford m 2 e 2 20

40

Table 8b (cont.)

Soils Maj or Limitations

Area (ha)

Soils of alluvial-colluvial plains derived

from sedimentary rocks and acid to intermediate

volcanics:

Seaforth, dark B horizon variant w 2 180


- duplex soils of alluvial plains

Calen m 2 w 2

Narpi w 2 t 2

Eton w 2

Sandiford m 2 w 2

Marian m 2 w 2

Marian, yellow B horizon variant m 2 w 2

- uniform clay soils of alluvial plains

Victoria Plains k 2 w 2

Brightley k 2 w 2


St. Helens

Cameron

f2 r2 t2 e2

m2 f2 t2 r2

12 490

2 860

1 310

5 290

6 050

1 340

8 760

7 300

1 210

1 340

TOTAL 55 340

41

Table 8c. Mapping units of class 3

Soils Major

Limitations Area

(ha)

Soils of uplands derived from acid crystalline tuffs:

Marwood

Munbura


intermediate intrusives and dykes:


Dunwold

Septimus

Gargett

Gargett, deep A horizon variant

Tannalo


Finch Hatton

Netherdale

Uruba

Farleigh

Kowari


m 3 n 3 w 3

m 3 e2_ 3

m 3 n 2 w 2 e2_ 3 t2_ 3

m 3 n 2 e 3

m 3 w 2 e2_ 3

m 3 n 2 w 3

m 3 e2_ 3 r 2 t 2

e 3 t 2 r 2

m 2 t2_ 3 e 3

m 2 r2_ 3 e 3

m 3 e2_ 3

m 2 r 3

m 2 t2_ 3 e2_ 3

310

910

3 620

40

3 650

420

1 210

1 480

520

1 740

2 590

270

210

42

Table 8c (cont.)

Soils Major Area Limitations (ha)

Soils of uplands derived from basic to intermediate volcanics:

Wagoora


Nabilla

Royston

Martin

Kungurri

Glenella

Habana

Silent Grove

Etowrie

Etowrie, neutral duplex variant

Soils of uplands derived from acid to intermediate volcanics:

Whiptail

Wollingford

Wollingford, intrusive parent material variant


Mentmore

Belmunda

e 3 r2_ 3 2 000

e 3 r2_ 3 270

m 2 r2_ 3 e2_ 3 890

r2_ 3 e2_ 3 650

m 2 r2_ 3 e2_ 3 t 2 770

k 2 e 3 r 2 40

r2_ 3 e2_ 3 1 790

m 2 r2_ 3 e2_ 3 t2_ 3 1 370

k 2 e 3 660

k 2 w 2 e 3 420

m 2 r 2 e2_ 3 90

m 3 r2_ 3 e2_ 3 t 3 s 2 4 ii0

m 3 r2_ 3 e2_ 3 t2_ 3 s2_ 3 5 980

m 3 r 2 e2_ 3 160

m 3 r2_ 3 e 3 1 040

m 3 r2_ 3 e2_ 3 t2_ 3 3 160

m 3 r2_ 3 e2_ 3 690

43

Table 8c (cont.)

Soils Major Limitations

Area

(ha)

Soils of uplands derived from sedimentary

rocks:

Pindi

Jumper

Kuttabul

Mulei

m 3 r2_ 3 e2_ 3

m 3 r2_ 3 e2_ 3 s 2

m 3 r2_ 3 e2_ 3

m 3 n 2 e2_ 3

5 370

1 420

5 380

280

Soils of alluvial-colluvial plains derived from sedimentary rocks and acid to intermediate volcanics:

Ossa

Ossa, cobbly variant

Seaforth

Seaforth, yellow B horizon variant

Balberra

Kuttabul, alluvial-colluvial variant

m 3 w 2 e2_ 3 r 2

m 3 r2_ 3

m 3 w 2

m 3 w 2

m 3 w 3

m 3 e 2

5 850

220

1 090

160

1 520

2 420



Calen

Narpi

Sunnyside

Sandiford

Mirani

m 2 t 3 w 2

s 3 t2_ 3 w 2

m 2 k 2 w 3

m 2 s3 w2

m 3 w 2

80

430

4 250

620

3 780

44

Table 8c (cont.)


Area (ha)

- uniform clay soils of alluvial plains

Victoria Plains

Brightley

Benholme

Dundula

- duplex soils of relict plains

Kinchant, coarse sandy variant

Allandale


St. Helens

Cameron

Murray

s2_ 3 k 2 w2_ 3

s2_ 3 k 2 w 2

k 2 w 2

s2_ 3 k 2 w 2

m 3 n 3 w 3

m 3 s 3 w 2

r2 f3 t3

m2-3 f2-3 t2-3 r2-3

m3 n2 f2-3 r2-3

1 080

700

1 070

1 310

1 230

230

ii0

1 300

1 010

Soils of the coastal dunes:

Andergrove

Andergrove, coarse sandy variant

Neils

m 3 n 2

m 3 n 2

m 3 s 3 w 3

780

120

280

TOTAL 83 150

45

Table 8d. Mapping units of class 4


Area (ha)

Soils of uplands derived from acid to intermediate intrusives and dykes:


Dunwold

Uruba, sandy A horizon variant


Finch Hatton

Netherdale

Uruba

Kowari


Soils of uplands derived from basic to intermediate volcanics:

Wagoora


Nabilla

Martin

Glenella

Habana

Silent Grove

m 3 n 2 t 3 w 2 e 4

m 3 t 3 e3_ 4 r2_ 3

r2_ 3 e 4 t2_ 4

m 2 t2_ 3 e 4

m 2 t 3 r2_ 3 e3_ 4

m 2 r 4 e 2

m 2 t 3 e 4

r2_ 4 e2_ 4

t2_ 3 r 3 e 3

m 2 t 3 r 4 e 3

m 2 r 3 e 4

r3_ 4 e3_ 4

m 2 r3_ 4 e3_ 4 t 3

k 2 r 4 e 3

30

90

160

280

390

20

i0

ii0

30

80

30

120

80

40

46

Table 8d (cont.)

Soils Maj or Limitations

Area

(ha)



Whiptail

Wollingford


Mentmore

Mentmore, sandy loam variant

Belmunda

m 3 r3_ 4 e3_ 4 t 3

m 3 t 4 r2_ 3 e3_ 4 s 2

m 3 s 4 e 2

m 3 t 3 r3_ 4 e2_ 4 s 4

m 4 r 3 e2_ 3

m 3 r 4 e 3

250

230

50

600

300

220

Soils of uplands derived from sedimentary rocks:

Pindi

Jumper

Palmyra

Kuttabul

m 3 r2_ 3 e 4

m 3 s 3 r 3 e 3

m 4 r 3 el_ 4

m 3 r2_ 4 e 4

90

ll0

690

140

Soils of alluvial-colluvial plains derived

from sedimentary rocks and acid to


Ossa, cobbly variant m 3 r 4 e 3 220

47

Table 8d (cont.)


Area

(ha)



Calen

Eton

- uniform clays of alluvial plains

Victoria Plains

Dundula

-duplex soils of relict plains

Kinchant


Cameron

Murray

m 2 s2_ 4 w2_ 4

s 4 w 2

s3_ 4 k 2 w 3

s 4 k 2 w 2

m 4 n 3 s 3 w 3

r3 f4

m3 n2 r3-4 f3-4 t3

60

50

170

140

1 570

330

340

Soils of the coastal dunes:

Andergrove

Andergrove, calcareous variant

m 3 n 2 t 3 w 4

m 3 n 2 t 3

300

20

TOTAL 7 350

48

Table 8e. Mapping units of class 5

Area

(ha)

Belmunda

Mountains and hills

Total - Unsuitable Uplands

230

106 960

107 190

Allandale, strongly sodic variant

Andergrove )

Andergrove coarse sandy variant ) Andergrove, calcareous variant and frontal dunes )

Mangroves and saltmarshes

Freshwater swamps

Streambeds

Gullied lands

Total - Unsuitable Lowlands

140

800

16 810

630

3 890

4 260

26 530

Urban and industrial

Dam

4 510

1 280

TOTAL 139 510

49

Plate 1: Urban development adjacent to caneland in North Mackay.

Plate 2: Soil conservation layouts on newly assigned land at Royston Park

51

Plate 5: Poor crop growth on marginal land in the Kinchant area because of moisture availability, soil nutrient, salinity and wetness limitations

Plate 6: Landscaping in the Cattle-Creek mill area includes bulldozing through a small hill in order to provide more land for assignment

53

5. INTERPRETATIONOFTHE DATA

5.1 Mapping scale

An understanding of the scale of mapping is important for correct interpretation of the data. The scale determines the density of sites visited and the smallest area of land that can be individually described and represented on a map. In this study the density of field observations was consistent with a scale of 1 : 50 000. That means the minimum area of land individually described was 6 to i0 ha.

Thus for any use that requires more detailed information, at a

larger scale, e.g., 1 : 4 000 as used by cane inspectors, further field inspection with a greater density of observations will need to be undertaken.

The scale of mapping adopted in this study is considered the most appropriate for regional planning.

5.2 Land use efficiency

Land use efficiency was calculated for the different land types at Rocky Point (Holz 1979), and Capelin (1979) identified the reduction of suitable land during development at Nambour. Holz (1979) used land

use efficiencies of 90%, 80% and 60% for land with slight, moderate

and severe wetness problems.

The land use efficiency is intended to account for the loss of land to headlands, drains, soil conservation works and general infrastructure. For every i00 ha of suitable land only a proportion will be used for

cane growing and this proportion varies according to land type and

land suitability.

Assigned land is measured by the cane inspectors at a scale of

1 : 4 000. Gullies, headlands, roads, drains, etc., are not included in the assigned land. Each uma was measured at a scale of 1 : 50 000 and headlands, drains, etc., cannot be differentiated at that scale and

so are included in the total area.

The concept of land use efficiency has been used in this study to estimate firstly the potential increase in assigned land and secondly (as adjusted mill factors) the area of assigned land in each uma.

54

Potential assigned land

The land use efficiency factor varies with the land suitability. As the severity of each limitation to canegrowing increases then more land is consumed in overcoming that limitation, e.g., increasing wetness requires a greater density of drains; small areas of stony land may be left uncultivated; broken topography may preclude cultivation of small gullies, etc.

The land use efficiency factors used include 0.9 for Class 1 land, 0.85 for Class 2, 0.75 for Class 3 and 0.6 for Class 4 land. That is, for every i00 ha of Class 2 land, there is potentially 85 ha of

assigned land.

Assigned land

The assigned land was measured at a scale of 1 : 50 000 after cane inspectors had delineated the boundaries on aerial photographs. This measured area includes error comprising the land use efficiency factor, drafting error, cane inspector's error in marking the aerial photographs and measuring error. The total error was calculated by comparing the total area of land assigned to each mill measured at 1 : 50 000 with that measured by the cane inspectors at 1 : 4 000. The ratio was called the mill factor (see Table 9). The mill factor varies among the six mills because of different cane inspector's error and the

different proportions of land types within each mill area.

Table 9. Mill factors for estimating assigned land

Mills

Farleigh Racecourse Pleystowe Marian Cattle Ck North Eton

Assigned

area

measured

at

1:50 000

Assigned

area

measured

at 1:4 000

(June,

1982)

20 608 na 15 834 ha 16 426 ha 23 571 ha 9 070 ha 12 657 ha

15 900 13 681 14 350 15 343 7 045 9 954

Mill .77 .86 .87 .65 .77 .78 factor

55

In order to account for the different proportions of land types

within each mill area, the mill factors were adjusted using the land

suitability classes (see Table i0). These adjusted mill factors are arbitrarily chosen to best estimate the assigned area of each mill and

to approximate the land use efficiency factors of 0.9, 0.85, 0.75 and

0.6. For example, the estimates of land assigned to Farleigh mill were derived by:

Total measured

area of

Class 1 609 ha x .9 (adjusted = 548 ha

mill 2 8 330 ha x .85 = 7 080 ha

factor) 3 9 868 ha x .77 = 7 598 ha

4 431 ha x .65 = 280 ha

5 641 ha x .64 = 410 ha

(estimated

assigned

area)

TOTAL 15 916 ha

which estimates 100.1% of the actual assigned area.

In summary, there are two uses of the areal data. Firstly, estimation of the assigned land involves using the adjusted mill factor

and secondly, estimation of the potential assigned land involves using

the land use efficiency factor.

5.3 Use of suitability classes

Land has a wide range of properties which affect yields, costs and efficiency of production. In Mackay, each of the 70 different soils identified has its own peculiarities with respect to crop production. The land suitability classification attempts to simplify these complex

interactions so that a comparative overview can be gained of Mackay's

cane producing lands. Although the classification simplifies the production characteristics in a logical manner, there is little quantitative information available. At this time it is not possible

to quantitatively compare the effects of different limitations, e.g.,

flooding vs. moisture availability vs stoniness.

In general, as the degree of limitation increases, yields decline

and/or costs of production increase and thus efficiency declines. However, the farmer has the major effect on yield and economic efficiency and we cannot assume that yields on Class 1 land will always be higher than those on Class 2 and 3 land though often that may be the

case. The reason for downgrading land, e.g., stoniness, may not directly affect yields but limit the use of machinery and thus reduce

the efficiency of farming that land. Lands with the same suitability

56

class may have different long term values to the sugar industry, e.g., Glenella soils downgraded to Class 3 due to erosion problems, will

remain highly productive after measures have been taken to combat erosion. In contrast, the Class 3 Andergrove and Pindi soils will never attain the productivity of the Glenella soils due to inherent

soil properties.

Considerable information is lost when simplifying the resource inventory for land suitability purposes hence the land suitability

classes should be interpreted with care.

Table i0. Adjusted mill factors for each suitability class

Mill

suitability Class Farleigh Racecourse Pleystowe Marian Cattle Ck North Eton

1 .9 .91 .93 .86 .92 .9

2 .85 .87 .9 .78 .87 .85

3 .77 .82 .855 .635 .82 .72

4 .65 .74 .745 .35 .65 .59

5 .64 .63 .695 .35 .65 .58

57

6. RESULTS

6.1 General

Information from the study is presented in two reports, in computer

files and on maps.

This land suitability report provides background information on the district and the cane industry; an explanation of the methods employed in collecting and analysing the data and highlights some of

the more salient results.

The computer files include descriptions of 1 994 sites and 2 225 uma's. For each site, landform and soil profile descriptions are

available. For each uma, resource and land suitability data are

available (see Appendix II).

The three maps enclosed have been prepared at a scale of

1 : i00 000.

Map i, Assigned Cane Land, was prepared in 1980 and shows the land

assigned to each mill as at February 1980. Tramways are also shown.

This information has been updated onto 1 : 50 000 base maps to accommodate the 1981-1982 expansion. Limited numbers of these i: 50 000 maps are available. The updated assignment data have been used in all areal calculations. Map 3 also shows the updated assigned

areas but they are not mill specific.

Map 2, Land Suitability for Sugar Cane, shows the land suitability class of each uma, the unique number of each uma, and the channels and pipelines of the Eton Irrigation Scheme. Each uma can be identified

from its number so that the specific limitations for any uma can be

determined from the uma data file (Appendix II).

Map 3, Land Use and Land Suitability, shows Class i, 2 and 3 land as agricultural land; Class 4 and 5 land as marginal and unsuitable agricultural uplands or lowlands; urban and industrial areas; National Parks, State Forests, Timber Reserves, Shire boundaries, the

Eton Irrigation Scheme, tramways and all assigned land (June 1982). This map is intended as a planning tool to present planners in local government, the sugar industry or State and Federal Governments with

an overview of the location, present use and potential of the

district's resources.

Prior to reading the results, it is advisable to read section 5

'Interpretation of the Data'. This should help avoid potential

misunderstanding.

58

6.2 Total land suitable for sugar cane

The total (measured) area of Class i, 2 and 3 land suitable for growing sugar cane in the long term is 143 140 ha (Table ii). A

further 7 350 ha is considered marginal for long term production. Class 1 land comprises 3.1% of the suitable land, with Class 2 comprising 36.6%, Class 3 comprising 55.4% and Class 4 comprising 4.9%.

Table ll. Total area of land in classes 1 to 4

Suitability class Area (ha)

1 4 650

2 55 340

3 83 150

4 7 350

The limitations to canegrowing for the suitable land are given in Table 12. The most significant limitations to canegrowing in this

district are moisture availability, wetness, erosion and stoniness.

Wetness affects some 77 020 ha but most of this land has only a slight

limitation. In contrast, most land affected by moisture availability (106 250 ha) and erosion (66 250 ha) has moderate to severe limitations. Stoniness affects some 47 180 ha, workability 29 220 ha, soil nutrient i0 550 ha, salinity 9 220 ha, topography 8 410 ha and flooding 4 780 ha.

The area shown as affected by salinity is an over-estimate of the actual area affected since it includes the total area of each uma in which salting/sodicity occurs. Each uma was downgraded depending on the number, size and severity of the outbreaks. Outbreaks which

severely affect cane growth are usually less than 1 ha in size although

their disruptive effect may extend over much larger areas. The area of only slightly affected land is largely unknown at this stage since

crop production is usually severley affected before the problem is

detected.

Table 12. Total area (ha) and severity of each limitation

Severity Limitation

moisture soil availability nutrient salinity topography workability stoniness wetness erosion flooding

(m) (n) (s) (t) (k) (r) (w) (e) (f)

2

(slight)

39 790 7 440 4 380 4 430 29 220 30 390 66 450 19 800 2 800

3

(moderate)

63 900 3 ll0 4 510 3 810 15 750 i0 290 45 090 1 400

4

(severe)

2 500 330 170 1 040 280 1 630 580

TOTAL 106 250 i0 550 *9 220 8 410 29 220 47 180 77 020 66 520 4 780

* Total area of the uma's in which salting may affect cane production, i.e., this is not the

actual area with observable salinity.

60

6.3 Characteristics of assigned land

Land suitability data can be extracted for the assigned land in each mill area. Data relating to the small areas of land assigned to Plane Creek (240 ha) and Proserpine (250 ha) have not been included.

The area of land in each suitability class assigned to each mill

is given in Table 13.

Table 13. Area of land in each suitability class assigned to each mill

Mills

Suitability Farleigh Racecourse

class (ha) (ha)

Pleystowe Marian Cattle North Total (ha) (ha) Creek Eton (ha)

(ha) (ha)

1 550 700 1 290 90 520 590 3 730

2 7 080 8 160 7 140 5 570 1 490 5 600 35 030

3 7 600 4 640 5 590 9 140 4 530 3 380 34 880

4 280 120 180 310 290 220 1 400

5 390 60 150 230 220 170 1 230

TOTAL 15 900 13 680 14 350 15 340 7 058 9 960 76 270

There are some significant differences in the proportion of Class i, 2, 3, 4 and 5 land among the six mills. Pleystowe, Racecourse and

North Eton mills have around 60% of assigned land as Classes 1 and 2 while Farleigh has 48%, Marian 37% and Cattle Creek 28%. Approximately 2 630 ha or 3.4% of all the assigned land is considered marginal or

unsuitable for long term cane production.

Table 14 lists the percentage of assigned land affected by each

limitation for each mill. While this information characterises each

mill area, a better understanding can be gained by considering the

severity of each limitation which is related to the soil and land types

found in each mill area.

61

For example, Farleigh and North Eton mill areas appear to have relatively low proportions of land with moisture availability limitations (50% and 56%) when compared with Racecourse mill area (79%). However, 34% and 31% respectively of these assigned lands have a moderate moisture availability limitation (m3). In contrast Racecourse mill area has only 23% with a moderate limitation but 55% with a slight

limitation (m2).

The Cattle Creek mill area has the highest proportion of assigned land affected by nutrient and topography limitations but has no major salinity problems. The nutrient problems are due to the large area of coarse textured soils derived from acid intrusives and the topographic problems are due to the attractive soils which occur on steep dissected lands. Cattle Creek mill area has a low proportion of land with a workability limitation and has only two small salting occurrences.

The North Eton mill area has a high proportion of land with a workability limitation reflecting the large area of clay soils on

alluvium.

The proportion of assigned land with stoniness limitations reflects the proportion of undulating land and geological formations in each mill area. Racecourse and North Eton mill areas have only low proportions of land with a stoniness limitation as both have large areas of soils derived from alluvium. The relatively low proportion of Cattle Creek mill area affected by stone indicates that the soils derived from acid to intermediate intrusives have less stone than do

soils from the other geological formations in the study area.

Most of the assigned land with a wetness limitation has only a

slight limitation due to the flat topography of the alluvial plains.

Racecourse mill area has little land with an erosion limitation but Marian, Cattle Creek and Farleigh mill areas all have significant

erosion problems.

Cattle Creek mill area has the highest proportion of land affected

by flooding which reflects the significance of the terraces and

floodplains of Cattle Creek to the mill area.

/

Table 14. The percentage of land assigned to each mill affected by each limitation

Mill

Moisture Soil availability nutrient Salinity Topography Workability Stoniness Wetness Erosion Flooding

(m) (n) (s) (t) (k) (r) (w) (e) (f)

Farleigh 50.1% 4.3% 6.2% 1.2% 19.8% 34.6% 41.6% 48.1% 3.8%

Racecourse 78.8 1.4 6.9 0.3 19.8 3.5 78.3 7.4 0.9

Pleystowe 64.9 0.6 5.8 2.3 17.9 30.0 46.4 40.2 1.6

Marian 70.3 5.1 5.1 5.7 12.0 38.6 42.6 53.4 2.9

Cattle Creek 70.6 21.9 0.0 24.6 4.8 21.3 39.3 52.5 7.4

North Eton 56.0 7.4 3.8 5.2 30.6 17.0 69.9 29.0 i.i

AVERAGE 64 . 9 5 . 3 5 . 1 4 . 9 17 . 9 25 . 4 52.8 38 . 3 3 . 0

63

Table 15 gives the percentage of assigned land within i0 km transport distance increments from each mill. These figures were obtained by measuring the distance from the labelling point of each

uma to points plotted at 5 km intervals along the tramway systems of each mill. The least distance from each labelling point to the mill was chosen and the area of assigned land within that uma was allocated that distance from the mill, i.e., the sum of the distances from the labelling point of a uma to the 5 km point on the tramway and 5 km

tramway point to mill. Road haulage was not considered and the area

distance figures do not necessarily reflect tonnages hauled. The data shows that all the land assigned to Cattle Creek mill lies within 20 km of the mill and that all of North Eton, 98% of Marian and 95% of Racecourse lie within 30 km. Pleystowe has 12% and Farleigh 45% of assigned lands within 40-70 km of the mill. The

weighted mean haulage distance from the land assigned to each mill indicates that on average Farleigh transports cane the farthest and Cattle Creek the least.

Table 15. The percentage of assigned land within specified distances from each mill

Mill

Weighted 0-i0 10-20 20-30 30-40 40-50 50-60 60-70 mean

distance (km) (km) (km) (km) (km) (km) (km) (km)

Farleigh 29% 19% 4% 3% 9% 21% 15% 30.6 km

Racecourse 16 51 28 5 - - - 15.9

Pleystowe 53 25 8 2 7 4 1 15.2

Marian 22 40 36 2 - - - 15.6

Cattle Creek 50 50 . . . . . 8.4

North Eton 49 20 31 . . . . 13.6

Current erosion is difficult to assess since regular cultivation

and earth-moving often disguise the effects of erosion. However, assessment of existing erosion was recorded for each uma. Table 16 gives the areas with little, observable or severe erosion for each

mill.

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Table 16. The area and severity of existing erosion on land assigned to each mill

Mill Existing erosion (ha)

Little Observable Severe

Farleigh 4 240 ha 2 720 ha 600 ha

Racecourse 610 120 60

Pleystowe 2 760 2 860 170

Marian 3 460 3 850 820

Cattle Creek 950 2 570 350

North Eton 2 430 ii0 170

TOTAL 14 450 12 230 2 230

Cattle Creek mill area has the worst erosion problem with 41.5% of assigned land with observable or severe erosion, while Marian has 30.4%, Farleigh 21.3%, Pleystowe 21.1%, North Eton 2.9% and Racecourse only 1.4%.

6.4 Characteristics of potential assigned land

If all land suitable for cane growing was available to the industry there is sufficient Class i, 2 and 3 land to facilitate an increase of 39 570 ha in assigned land (after taking the land use efficiency factor into account). Table 17 shows the suitability classes of this potential increase in assigned land.

Table 17. The area and suitability class of the potential assigned

land

Suitability Class Area (ha)

1 430

2 12 010

3 27 130

4 2 880

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It is outside the scope of this study to estimate the area of land which would be available for future industry expansions since this is dependant on owner attitudes, possible alternative uses and the economics of the cane industry. Thus, these figures provide only a base for future estimates of expansions.

The most productive and economically efficient suitable lands have already been developed for sugar cane. Table 18 indicates the different proportions of each land suitability class for assigned land and potential assigned land. The potential assigned land is relatively less attractive than the assigned land.

The percentage distribution of the limitations of the potential assigned land are given in Table 19. This potential assigned land has a greater proportion of all the limitations to cane growing, in particular moisture availability, soil workability, stoniness and erosion.

The potential assigned land was allocated to its nearest mill using the existing tramways. This data shows the potential assigned land is located farther from the mills than assigned land (Table 20). The district weighted mean haulage distance for assigned lands in 18.2 km while that for potential assigned lands is 23.4 km. Suitable land close to each mill is less likely to be available to the industry due to the higher demand on this land for alternate uses.

Some of the more significant areas of potential assigned land are discussed below. These areas are indicated on Map 3, 'Land Use and Land Suitability'

In the Sunnyside-Munbura area there are alluvial plains and undulating rises suitable for expansion. The soils on the undulating rises are developed on acid crystalline tuffs and the major limitations are moisture availability and soil nutrients while on the alluvial plains wetness is a limitation. This area may be served by water from the Eton Irrigation Scheme which will be particularly beneficial to crop production on the undulating rises.

There is potential for expansion in the Palmyra to Homebush area on mostly undulating rises where the major limitations are moisture availability, erosion and stoniness. There is a probability of some secondary salting developing in lower slope positions following

development.

Land in the Markeys Road - Kinchant area on relict plains is considered only marginal for long term cane production. A limitation in these soils is moisture availability which can be overcome to some extent by the generally good supplies of underground water in the area.

However, these soils are also strongly sodic, have soil nutrient limitations and an impermeable, cemented pan occurs at around 1 m depth. There is cause for concern over the development of secondary

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Table 18. Percentage distribution of suitability classes within assigned and potential assigned land

Suitability class Assigned land %

Potential assigned land %

1 5 1 2 46 28 3 46 64 4 2 7 5 1

Table 19. Percentage distribution of limitations within assigned and potential assigned land

Limitation Assigned land %

Potential assigned land %

moisture availability (m) 65 77 soil nutrient (n) 5 9 salinity (s) 5 7 topography (t) 5 6 workability (k) 18 26 stoniness (r) 25 39 wetness (w) 53 55 erosion (e) 38 51 flooding (f) 3 4

Table 20. The percentage of assigned and potential assigned land within specified distances from the mills

Distance Assigned Potential land assigned

land

0-i0 km 34 15 10-20 34 37

20-30 18 21 30-40 3 i0 40-50 3 3 50-60 8 14

Weighted mean 18.2 km 23.4 km distance

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salting in this area depending on such factors as the intensity of irrigation, the quality of irrigation water, drainage and the use of soil ameliorants such as gypsum. Some soils in the area are unsuitable for canegrowing.

The potential for expansion in the Mia Mia area is mostly on undulating rises with erosion and stoniness limitations. There are also some alluvial plains with wetness limitations.

Potential expansion areas in the upper Pioneer area beyond Pinevale comprise stream terraces and gently undulating plains of alluvial- colluvial material derived from acid to intermediate intrusives and dykes. Rainfall is lower here than for Mackay and development for sugar cane is probably only possible with irrigation.

The "Vales" area south-west of Pinnacle is mostly rolling rises with some stream terraces. Most of this area is considered marginal for long term cane production due to the difficulty in controlling erosion on the steep slopes and highly erodible soils. The stream terraces have flooding and stoniness limitations.

West of Mirani through Benholme to Dunwold are relict plains, undulating rises and alluvial flats. The soils of the alluvial flats have mainly soil workability and wetness limitations while the coarser textured soils of the relict plains and undulating rises have moisture availability and nutrient problems. There may be some danger of salinity/sodicity problems developing on the relict plains since they appear to have had a similar genesis to the soils of the Kinchant area.

There is some scope for expansion along Doyles road in the Devereaux Creek area. The major limitations are moisture availability and erosion on the long slopes.

North of Habana, adjacent to the coast, there are undulating rises and alluvial flats suitable for expansion. The major limitations are stoniness, moisture availability and erosion on the uplands with wetness on the lowlands. Saltwater intrusion may also develop in this

area.

The land from Constant Creek to Belmunda comprises undulating rises with moisture availability, sotniness and erosion limitations while the alluvial flats have wetness limitations. Saltwater intrusion may become a problem on the alluvial flats if they are developed for

cane growing.

The potential expansion areas west of Seaforth are predominantly undulating rises with moisture availability, stoniness and erosion problems though some areas of better agricultural soils have only

stoniness limitations.

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East of Narpi are gently undulating plains with long alluvial- colluvial slopes. The major limitations are moisture availability and erosion.

Most of the better agricultural soils in the Royston Park area have already been developed but there is some expansion potential on the alluvial flats where the major limitations are wetness and soil workability.

The Silent Grove area has fine textured soils on gently undulating plains where the major limitations are soil workability and erosion.

The Mentmore area includes much land suitable for canegrowing. The undulating rises suffer mostly moisture availability, stoniness and erosion limitations though some better soils suffer only from stoniness. The alluvial flats have wetness and moisture availability limitations. The rainfall regime is largely unknown in this area but should be sufficient for dryland sugar cane.

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7 . CONCLUSIONS AND RECOMMENDATIONS

i. There is substantial scope for expansion in all mill areas except Cattle Creek. There is sufficient land suitable for cane growing to accommodate a 50% expansion in the area of assigned land. However, the following points should be considered:

a) no account has been taken of suitable land not available to the industry. There are no doubt a significant number of land owners with suitable land who do not intend to use their land for cane growing.

b) the potential assigned land is on average, less attractive than the assigned land, i.e., lower less reliable yields and/or higher production costs per unit of assigned area could be expected.

c) the potential assigned land is on average further from the mills than the assigned land.

d) all new caneland should be treated with appropriate soil conservation measures to control soil erosion.

2. There are approximately 1 230 ha of assigned land which are considered unsuitable for growing sugar cane in the long term, mainly due to soil erosion. The assignments from these lands should be transferred to suitable unassigned areas.

A further, approximately 1 400 ha of assigned land are considered marginal for growing sugar cane in the long term. These lands are of dubious benefit to the industry due to high cost of and/or unreliable production and land degradation.

3. The area affected by acute salinity/sodicity outbreaks is relatively small at present, but is increasing. Their importance is amplified by their disruptive effects on regular farming practices. Further research into their development should improve the effectiveness of ameliorative measures.

4. The problems of soil erosion have been recognised by the sugar industry. However, the rate of implementing control measures has to be increased if all eroding assigned land is to be treated within a reasonable time.

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There is a need to develop alternative viable strategies to control soil erosion on land which has topography not conducive to implementing the traditional soil conservation measures. In particular, the trash conservation and minimum tillage research programme should develop techniques basic to sound farming practices such as effective fertilizer application, appropriate planting techniques and weed control.

5. There is a diss trend to less fallow ground and more plough- out re-plant crops. Soil organic matter levels are already low in many soils. Practices which could reduce these levels further should be discouraged.

6. The mills should rationalise the location of their assigned lands with respect to transport. This is particularly evident between Narpi and Wagoora where cane is transported by road or rail to Farleigh, Pleystowe and Marian mills from adjacent or nearby blocks of cane.

7. The following comments cover wider land use concerns:

a) the mangroves and saltmarsh communities fringing the coast should be retained as fisheries habitats.

b) there are significant areas of frontal dunes which should be carefully managed. They have fragile ecosystems which form an integral part of beach stability.

8. There is intense competition for land surrounding Mackay. Land is required for urban and industrial growth and for the sugar industry. The dilemma facing local planners is that on one hand, valuable agricultural land is a limited resource and it is in the community's interest to preserve this land for agriculture in the long term while on the other hand, land must be found to accommodate the urban and industrial growth.

The land resource inventory and land suitability data compiled in this study provide the basic information for integrated regional planning, i.e., planners now know what is available, where it is, how much there is of it and what are its potential uses. Informed decisions can be made with respect to preservation of valuable agricultural land, the allocation of land for urban and industrial development and identifying environmentally desirable or fragile areas.

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8 . ACKNOWLEDGEMENTS

Thanks are due to many people involved in the sugar industry and in the Department of Primary Industries for their assistance during the course of the study and preparation of the report. In particular:

Messrs Mike Haysom, Les Chapman, Eddie Pembroke and the Extension staff of BSES in Mackay for technical information.

Mr Kerry Rosenthal for technical advice and computing assistance.

Mr Garry Finney for drafting services.

Cane inspectors from each of the six mills for supplying the cane assignment data and for many other miscellaneous requests for information.

Mr Renatis Ebersohn for assistance during the mapping phase of the study.

Miss Pat Adair, Mrs Gayle Nielsen and Miss Sheena Wells for the typing the many drafts.

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9. REFERENCES

Anonymous (1981), 'It's mighty stoney', Australian Canegrower, 3 (7), 34.

Bieske, G.C. (1967), 'Response to Irrigation at Fairymead', Proceedings of Queensland Society of Sugar Cane Technologists, Thirty- fourth Conference, 81-86.

BSES (1977), 'Assessment of flood damage in the Mulgrave and Babinda areas, 1977', Internal Report. Bureau of Sugar Experiment Stations. Queensland, Australia.

Capelin, M.A. (1979), 'Moreton Mill Area - a sugar cane land suitability study', Division of Land Utilisation Technical Bulletin, No 37, Queensland Department of Primary Industries.

Chapman, L.S. (1977), 'Fertilizing cane - what are our objectives?', Proceedings of Queensland Society of Sugar Cane Technologists, Forty-fourth Conference, 155-160.

Chapman, L.S. (1980), 'Long-term responses in cane yields and soil analyses from potassium fertilizer', Proceedings of Australian Society of Sugar Cane Technologists, 1980 Conference, 63-69.

Chapman, L.S. (1982), 'Estimating sugar yield responses from N, P and K fertilizers in Queensland', Proceedings of Australian Society of Sugar Cane Technologists, 1982 Conference, 147-153.

Chapman, L.S. and Chardon, C.W. (1979), 'An evaluation of irrigation at Mackay', Proceedings of Australian Society of Sugar Cane Technologists. 1979 Conference, 117-123.

Elliott, J.T. and Pembroke, E.A. (1949), 'History of sugar in the Mackay district', Proceedings of Queensland Society of Sugar Cane Technologists, Sixteenth Conference, 155-160.

Fuelling, T.G. (1979), 'Cane transport from wet cane fields', Proceedings of Australian Society of Sugar Cane Technologists, 1979 Conference, 81-87.

Gosnell, J.M. (1971), 'Some effects of a water-table level on the growth of sugar cane', Proceedings of International Society of Sugar Cane Technologists, Fourteenth Conference, 841-849.

74

Ham, G.J. (1969), 'Water requirements of sugar cane', Water problems in tropical Queensland, Water Research Foundation of Australia, Symposium, Toowoomba.

Ham, G.J. and Chapman, L.S. (1982), 'A review of salinity related drainage problems in cane in the central region', Proceedings of Australian Society of Sugar Cane Technologists, 1982 Conference, 77-81.

Holz, G.K. (1979), 'Rocky Point. A sugar cane land suitability study', Division of Land Utilisation Technical Bulletin, No 38, Queensland Department of Primary Industries.

Holz, G.K, and Shields, P.G. (1985), 'Mackay Sugar Cane Land Suitability Study. Part 1 Land Resource Inventory', Queensland Department of Primary Industries Land Resource Bulletin, QV85001.

Isis Land Use Study Committee (1971), 'The Isis District, Queensland. A land use study', Queensland Department of Primary Industries.

Juang, T.C. and Uehara, G. (1971), 'Effects of ground water-table and soil compaction on nutrient element uptake and growth of sugar cane', Proceedings of International Society of Sugar Cane Technologists. Fourteenth Conference, 679-687.

Kingston, G. (1972), 'An experiment in irrigation scheduling - further comments', Proceedings of Queensland Society of Sugar Cane Technologists, Thirty-ninth Conference, 143-151.

Kingston, G. and Chapman, L.S. (1975), 'Water requirements and irrigation scheduling of sugar cane in Queensland. II. Irrigation scheduling of sugar cane in Queensland', Proceedings of Queensland Society of Sugar Cane Technologists, Forty- second Conference, 69-76.

Kingston, G. and Ham, G.J. (1975), 'Water requirements and irrigation scheduling of sugar cane in Queensland. I. Water requirements of sugar cane in Queensland', Proceedings of Queensland Society of Sugar Cane Technologists, Forty-second Conference, 57-67.

Lowndes, A.G. (1957), The drainage of sugar cane lands in N.S.W. Published by C.S.R. Co. Ltd.

Lowndes, A.G. (1965), Drainage of sugar cane lands in north Queensland, Published by C.S.R. Co. Ltd.

Maclean, N.R. (1976), 'Soil compaction studies in the Goondi mill area', Proceedings of Queensland Society of Sugar Cane Technologists, Fourty-thi~d Conference, 103-109.

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Maclean, N.R. (1977), 'Relationship between water-table height and cane yield in the Goondi mill area', Proceedings of Queensland Society of Sugar Cane Technologists, Forty- Fourth Conference, 105-110.

McIntosh, G.E. (1977), 'Grower solutions to drainage problems in the Victoria mill area', Proceedings of Queensland Society of Sugar Cane Technologists, Forty-fourth Conference, 119-124.

Northcote, K.H. and Skene, J.K.M. (1972), 'Australian soils with saline and sodic properties', Soil Publication No 27. Commonwealth Scientific and Industrial Research Organization, Australia 1972.

Pembroke, E.A. (1982), 'Frost inthe Central District', Cane Grower's Quarterly Bulletin, 46, (2) 57-59.

Pink, H.S. (1975), 'Land and water management on cane farms', Proceedings of Queensland Society of Sugar Cane Technologists, Forty-second Conference, 85-89.

Queensland Department of Primary Industries and Irrigation and Water Supply Commission (1975), 'Report on Eton Irrigation Project', February, 1975. Government Printer, Brisbane.

Robinson, F.E. (1963), 'Soil moisture tension, sugar cane stalk elongation and irrigation interval control', Agronomy Journal, 55, 481-484.

Rosser, J., Swartz, G.L., Dawson, N.M., Briggs, H.S. (1974), 'A land capability classification for agricultural purposes', Division of Land Utilisation Technical Bulletin, No 14, Queensland Department of Primary Industries.

Rudd, A.V. and Chardon, C.W. (1977), 'The effects of drainage On cane yields as measured by water-table heights in the Macknade mill area', Proceedings of Queensland Society of Sugar Cane Technologists. Forty-fourth Conference, 111-117.

Sallaway, M.M. (1979), 'Soil erosion studies in the Mackay district', Proceedings of Australian Society of Sugar Cane Technologists 1979 Conference, 125-132.

Sallaway, M.M. (1980), 'Effect on soil movement of continued cultivation into the wet season', Proceedings of Australian Society of Sugar Cane Technologists, 1980 Conference, 51-54.

Smith, C.D. (in preparation). 'Mary River - Tinana Creek Land Use Study', Queensland Department of Primary Industries, Land Resource Bulletin,

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Uilman and Nolan Pty Ltd (1978), study of the effects of urban expansion on cane growing lands, Mackay, A report to the Co-ordinator General, Queensland.

Vega, S.V. (1977), 'Effect of excess sodium on sugar cane yield', Proceedings of International Society of Sugar Cane Technologists, Sixteenth Conference, 861-866.

White, B.J. (1979), 'Climate, sugar yields and irrigation responses in Queensland', Proceedings of Queensland Society of Sugar Cane Technologists, Thirty-seventh Conference, 57-64.

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APPENDIX I

Explanation of codes for the uma data file

Location

Eastings. Australian Map Grid (AMG) reference for a labelling point within the unique map area (uma).

Northings. AMG reference for the same point within the uma.

Zone. A code for the zone designation of the AMG. The survey area is entirely within Zone SF55 coded as "55".

Resource inventory

Uma number. A numeric code assigned sequentially from the first uma described through to the last (i to 9999).

Mapping unit name. Based on the dominant soil (soil profile class). Symbols are from the legend on the soil map.

Geological reference. Map symbols from the Proserpine and Mackay 1 : 250 000 geological series.

Parent material. Indicates alluvial-colluvial material.

Soils -variability. i. Relatively homogenous, similar agricultural soils associated. 2. Relatively homogenous, dissimilar agricultural soils associated. 3. Relatively heterogenous, similar agricultural soils associated. 4. Relatively heterogenous, dissimilar agricultural soils associated.

Associated soils. Codominant and/or minor associates.

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Landform.

Erosional terrain -

Relative relief Slope

LP Level plain < 9 m < 1%

GP Gently undulating plain < 9 m 1 - 3%

UP Undulating plain < 9 m 3 - 10%

RP Rolling plain < 9 m i0 - 32%

B Badlands < 9 m > 32%

GR Gently undulating rises 9 - 30 m 1 - 3%

UR Undulating rises 9 - 30 m 3 - 10%

RR Rolling rises 9 - 30 m I0 - 32%

SR Steep rises 9 - 30 m 32 - 56%

B Badlands 9 - 30 m > 56%

UL Undulating low hills 30 - 90 m 3 - 10%

RL Rolling low hills 30 - 90 m i0 - 32%

SL Steep low hills 30 - 90 m 32 - 56%

VL Very steep low hills 30 - 90 m 56 - 100%

B Badlands 30 - 90 m > 100%

UH Undulating hills 90 - 300 m 3 - 10%

RH Rolling hills 90 - 300 m i0 - 32%

SH Steep hills 90 - 300 m 32 - 56%

VH Very steep hills 90 - 300 m 56 - 100%

PH Precipitous hills 90 - 300 m >,100%

RM Rolling mountains > 300 m i0 - 32%

SM Steep mountains > 300 m 32 - 56%

VM Very steep mountains > 300 m 56 - 100%

PM Precipitous mountains > 300 m > 100%

* Source: Speight, J.G. (1984), 'Landform', Australic~ Soil and Land Survey Handbook, McDonald, R.C., Isbell, R.F., Speight, J.G.,

Walker, J. and Hopkins, M.S. (Inkata Press, North Clayton, Victoria).

Aggraded terrain -

LA

LM

FL

SP

DB

LE

TS

TT

TU

TV

SB

Plain, alluvial

Plain, marine

Flat, alluvial and alluvial-colluvial, localised

Swamp

Coastal dune, beach ridge and foredune

Levee

Terrace, stream (level i)

Terrace, level 2

Terrace, level 3

Terrace, level 4

Stream-channel (streambank and bed)

Slopes. Minimum, modal and maximum slopes of the uma estimated

in per cent.

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Erosion assessment (EA).

0 - no significant water erosion.

1 - little evidence of erosion; land probably suffers minor sheet

and rill.

2 - observable erosion; including soil deposition, minor gulliest

eroded furrows and exposed subsoil in cultivation.

3 - severe erosion; gullies developed.

4 - stream bank erosion.

Salt affected soils (SAS).

F - saline/sodic patches associated with uplands; i.e., usually

footslopes and nearby alluvium.

P - saline/sodic patches on alluvial plain.

I - saline patches due to seawater intrusion.

Land suitability

Limitations to cane production.

m - moisture availability

n - soil nutrient

s - salinity/sodicity

t - topography

k - soil workability

r - stoniness

w - wetness

e - erosion

f - flooding

Land suitability class

i. Land suitable for long term sugar cane production with no

limitations. 2. Land suitable with slight limitations.

3. Land suitable with moderate limitations.

4. Land marginally suitable with severe limitations.

5. Land not suitable for long term production of sugar cane.

Areas

Total area. Total area of each wna.

Estimated assigned area. Estimated existing assigned area in each uma. (ie measured area multiplied by the adjusted mill factor)

Potential assigned area. Estimated potential assigned area in each uma. (ie measured area multiplied by the land use efficiency factors)

Alienatedland. Land in each uma used for infrastructure and/or

not suitable for cane production.

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Identity

Survey code. MCLS - Mackay Sugar Cane Land Suitability Study.

Record type number. Number 23.

mackay sugar cane land suitability study - part 2 - land ... · the sugar industry began in mackay...

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