icfr kwazulu-natal midlands regional field day · sites were situated in the kwazulu-natal midlands...

Thanks are extended to Sappi, NCT and Masonite for sponsoring the catering,

and EcoGuard for sponsoring drinks.

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ICFR KwaZulu-Natal Midlands Field Day Page | 2 © ICFR 2013

ICFR KZN Midlands Regional Interest Group Field Day

Date: Wednesday 29th May 2013 Venue: Mondi Mountain Home Nursery, Hilton (GPS: -29.566350, 30.272110) Time: 08h30 for 09h00

PROGRAMME

08h30 Meet for tea and coffee Indoor Presentations

09h00 Welcome and objectives of the field day Paul Viero Mondi

09h10 Post-establishment weed control in pines and eucalypt stands

Dr Keith Little ICFR

09h30 Air-drying rates: Eucalyptus smithii logs Trevor Morley ICFR

09h55 Genetic gain in production seed orchards of Acacia mearnsii: Half rotation results

Dr Julian Moreno Chan

ICFR

10h25 Rooting vegetative cuttings of Acacia mearnsii selections: Lessons from two commercial nurseries

Dr Michael Bairu ICFR

10h55 TEA

11h30 Nutrient depletion threshold study proposal Dr Steven Dovey ICFR

12h00 Growth responses to mid-rotation fertilisation of Eucalyptus pulpwood stands: Final results Dr Louis Titshall ICFR

12h30 A web-based microclimatic measurement and evaporative cooling control system for shade-netted forestry nurseries

Nkosinathi Kaptein ICFR

13h00 The land reform process: Government’s proposal Roger Godsmark FSA

13h30 LUNCH

14h15 Mondi’s Seed Extraction Facility and Research Nursery Dr Marius du Plessis Mondi

15h30 End of field day

15h30-16h00

Hot chocolate & snacks

16h00 KZN SAIF AGM


Post-establishment weed control in pines and eucalypt stands

Keith Little

[email protected]

Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209

Introduction

Previous research has focussed mainly on the competitive effects of vegetation on tree growth during the

establishment phase. In most plantations, shading at canopy closure reduces growth of competing

vegetation and the need for further management. Sometimes full canopy closure is delayed or not

achieved, and competitive vegetation may develop. This may occur due to one or a combination of the

following factors:

• A small leaf surface area;

• A low planting density;

• Thinning and pruning;

• Stress induced leaf senescence;

• Occurrence of shade tolerant vegetation; or

• Poor stocking.

Two pine and two eucalypt trials were initiated to determine the competitive effect of post-establishment

vegetation on tree growth, and at what stage this vegetation should be controlled (if competitive).

Description of Trials

Species P. patula P. tecunumanii E. grandis E. grandis x E. camaldulensis

Location Dargle Plantation, KZN-Midlands

Kwambonambi Plantation, KZN-Zululand

Clan Plantation, KZN-Midlands

Zenith Estates, KZN-Zululand

Age of trees when treatments initiated 4.5 years 2.9 years 4 years 2 years

Age of trees when last measured

18.5 years (trees thinned)

17.5 years (trees thinned)

9 years (trees felled)

7 years (trees felled)

Trial Design and Treatments

The trials were imposed on stands of trees that had been maintained in a weedfree state until the

treatments were initiated. For the pines this was timed to coincide with the first pruning operation, and in

the eucalypts with canopy closure.


Pine Treatments

Treat. No. Treatment Weeds removed 1 Weedfree All 2 Herbaceous weeds Woody weeds removed 3 Woody weeds Herbaceous weeds removed 4 Operational weeding Woody weeds removed prior to pruning and thinning 5 Weedy None

Eucalypt Treatments

Treatment Year treatments imposed

Age when treatment imposed (yrs)

Years kept weedfree

Years in a weedy state before weeding

1 December 1998 4 9 0 2 December 1999 5 8 1 3 December 2000 6 7 2 4 December 2001 7 6 3 5 December 2002 8 5 4 6 December 2003 9 4 5

Results:

Results obtained for both the pine and eucalypt trials were similar, and as such, only one set of data is

used to illustrate tree growth responses.

Figure 1. Eucalyptus grandis x E. camaldulensis basal area development at Zenith Estate,

Zululand, KwaZulu-Natal.

0

5

10

15

20

25

30

0 500 1000 1500 2000

Time after treatment initiation (days)

Basal are

a (m

2 h

a-1)

Weedfree

Weedy


Figure 2. Pinus patula basal area development at Dargle Plantation, KwaZulu-Natal Midlands.

Take Home Points

� From a tree growth perspective, the results indicate that the impact of vegetation on post-

establishment performance of trees is minimal.

� While this is an encouraging result for foresters, it must be acknowledged that on other sites and

with other eucalypts/pines, where the vegetation spectrum may be different, competition may

occur.

� It is recommended that selective control of woody and invasive plants is carried out where

competitive vegetation persists throughout stand development.

� Control of invasive aliens is required by legislation and therefore must be carried out, and this,

together with the control of other woody plants, will help to:

1. Reduce under-canopy fuel loads and risks of uncontrolled fires;

2. Reduce the seed bank of unwanted vegetation, and prevent their re-establishment; and

3. Improve access for silvicultural operations.

0

5

10

15

20

25

30

35

1600 2600 3600 4600 5600 6600

Time after treatment initiation (days)

Weedfree

Herbaceous weeds remain

Woody weeds remain

Operational weeding

Weedy

Basal area (m2

ha-1)


Air-drying rates: Eucalyptus smithii logs

Trevor Morley

[email protected] Institute for Commercial Forestry Research, P.O. Box 100281, Scottsville, Pietermaritzburg, 3209

Summary

Results of a trial to investigate the air-drying rates of Eucalyptus smithii logs stacked and left infield, at six

sites during the period May – October 2012, will be presented. Sites were situated in the KwaZulu-Natal

Midlands at Lidgetton, Richmond and Baynesfield on the NCT farms Ingwe (three sites), Enon (two) and

Baynesfield (one) respectively. Two sites were initiated monthly for the three month period May – July

2012

Upon each site initiation, forty trees were selected across the diameter range, with 20 trees debarked and

20 trees left with bark on. Felled trees were measured for volume determination and disks used for basic

density purposes. All trees were crosscut at 2.4 m log lengths and the logs stacked infield for weighing.

At each site, logs were massed individually at weekly intervals until six weeks after felling. Where

possible thereafter, all sites barring one, had log masses measured approximately fortnightly up until 12 -

16 weeks after felling, at which time disks were collected for moisture content determination and air-

drying rate purposes.

Further information and the results of this work will be presented.


Genetic gain in production seed orchards of Acacia mearnsii:

Half rotation results

Julian Moreno Chan


Summary

With the aim of measuring performance and realised genetic gain of twelve production seed orchards

(PSOs), a trial series was established between 2005 and 2007 including two sites in KwaZulu-Natal and

one in Mpumalanga. The orchards included in the study were established over the period 1972–2001 and

thus represent different stages of the breeding programme. Orchards were benchmarked against three

standard unimproved controls. Traits assessed included diameter, height, tree volume, survival, basal

area and volume per hectare, as well as stem quality and disease occurrence as measured at half

rotation.

All the seed orchards showed superiority over the controls across growth traits and sites, however

statistical differences among orchards were mostly non-significant. PSO 7 had the largest overall gain in

volume per hectare relative to the unimproved material (average 41% across sites), followed by PSOs 8,

9 and 13 with 32-34% average gains. The rest of the PSOs had average gains between 14-29%.

Orchards generally showed a higher percentage of straight stems and a lower proportion of malformed

trees than the controls but there were no clear differences among orchards in stem straightness. In

contrast, orchards did not show superiority over the controls in terms of stem defects and disease

incidence. The lack of statistically-significant site x orchard interaction effects, together with the

inconclusive effect of orchard site location on site performance prevent the ICFR from making

recommendations to the wattle growers as to what orchard seed should be used at specific sites.

All orchards established in the period 1997-2001 (PSOs 11-17, with the exception of PSO 13) showed

lower gains than the orchards established in the 1980’s (PSOs 7-9) implying a lack of progression in

volume improvement. Some of the possible causes are discussed but this is a complex issue involving

the genetic origin of the different orchards.

Unfortunately, the best performing orchards have been either terminated (mainly due to age) or are in

poor condition (low stocking and/or wind damaged). The four remaining orchards that are currently in

productive condition (PSOs 10, 11, 14 and 16) should provide satisfactory gains across the different

growing areas.


Rooting vegetative cuttings of Acacia mearnsii selections:

Lessons from two commercial nurseries

Michael Bairu and Sascha Beck-Pay


Summary

An attempt was made to root several cuttings using epicormic shoots of elite selections during 2011 and

2012 in two commercial nurseries. The objective was to capture and maximise the genetic gain by

establishing clonal seed orchards of selected individuals from the new breeding sub-populations; with the

aim of establishing new elite orchards in 2014. Some cuttings were also to be used as production hedges

as a source of material for future secondary cuttings as well as being used to establish a potted seed

orchard to undertake controlled cross experiments to maximise genetic advancements. The main purpose

of these trials was not experimentation, but observational data was recorded and analysed to improve our

knowledge on this difficult to root species. As was the case with previous attempts to root wattle through

cuttings, very poor rooting (< 11%) was recorded in both nurseries. However, due to the large number of

initial cuttings set, sufficient material (± 600 rooted cuttings) was produced to address the trial objectives

outlined above. Factors which could have possibly influenced the results will be discussed.


Nutrient depletion threshold study proposal

Steven Dovey


Summary

Nutritional sustainability research has indicated some major areas of concern and knowledge gaps. One

of these is the lack of a definitive soil-based indicator of site nutrient supply potential under plantation

forests that can be linked to tree productivity in the short, medium or long-term. This is due to the link

between laboratory-based soil nutrient status and plant-available nutrient status not being clearly defined

for plantation forests soils. Two research strategies have been proposed and will be implemented in

2013. One approach will involve a field assessment of soil nutrient supply and the other a pot trial

assessment of soil nutrient availability.

The field study will entail a multisite research trial series that will attempt to ascertain the level of site

nutrient loss required to produce measurable evidence of the onset of nutrient depletion. Trials will use

high density plantings, initially removing all tree biomass followed frequent biomass removal (annual

harvesting) to induce rapid nutrient loss in the soil. After the soil has become depleted, the sites will be re-

planted using standard planting practices, to test the depletion effects under operational conditions. This

study will develop a measure of soil nutrient supply and link this with tree performance and nutrient

status. It will also be used evaluate the ability of the sites to recover naturally, and with fertiliser addition.

A pot research trial is proposed, using seedlings grown in small pots, that investigates depleting individual

nutrients of various forestry soils. Soils will be taken from the 0-30 soil layer of established forestry sites.

The study will use fertiliser to supply all plant nutrient requirements, with single nutrient element omission

forming the basis of the treatment structure. The soil will be tested using standard laboratory analyses to

determine whether laboratory measures are capable of indicating differences between soils of adequate

and inadequate nutrient supply. Depleted and non-depleted soils will be stored for further laboratory

method development.

These experiments will form part of ICFR nutrient sustainability research and will enable the calibration of

tree-related nutrient responses with laboratory based measures for each soil type assessed.


Growth responses to mid-rotation fertilisation of Eucalyptus pulpwood stands:

Final results

Louis Titshall


Introduction

Fertilisation is one of few forestry management inputs that has the potential to alter site productivity

dramatically and immediately through increased nutrient availability (Titshall et al., 2012). While the

effects of fertiliser application at planting of eucalypt plantations has been thoroughly investigated over a

wide range of conditions, the effects of mid- to late-rotation application of fertiliser on the productivity of

Eucalyptus pulpwood stands has not been extensively investigated (Germishuizen, 2007). Some of the

benefits of mid- to late- rotation fertiliser application may include increases in final tree volume, reduction

in rotation length (reduced risk) and reduced investment losses associated with fertilising earlier in the

rotation. Therefore, a series of trials was established to investigate the productivity responses to fertiliser

application two to three years prior to clear-felling of eucalypt pulpwood stands, across a wide range of

sites (Table 1 ). This presentation reports on growth data and economic analysis from this trial series.

Trial Design and Treatments

Treatments

• Each site had three treatments (Table 2 ) with a single replicate (n = 2)

• Each treatment plot consists of 6 x 6 inner measured trees with buffer tree surrounds

• Granular fertiliser was broadcast-applied in rainy season (summer) (Table 2 )

• Diameter at breast height (DBH) was measured at prior to fertiliser application and frequently

thereafter

• Sample volumes were determined at rotation end and site specific regression determined for final

volume determination and converted to tons ha-1 for the cost-to-benefit analysis


Table 1. A summary of trial details of the Eucalyptus pulpwood mid-rotation fertilisation trials (Figure 1 ).

MRF Site Location Species

MAP MAT Alt. Lith.

Planted density

Age at fertilis.

Age at felling

Assessment period

mm 0C masl Stems per ha -------------------Months------------------

1 Canewoods E. grandis x E. urophylla 1153 21.9 71 Sand 1333 54.7 82.4 27.7

2 Ixopo E. dunnii 781 17.1 1118 Dolerite 1667 99.1 126.1 27

3 Ixopo E. dunnii 834 16.3 1354 Shale 1667 99.1 126.1 27

4 Dukuduku E. grandis x E. camaldulensis

919 21.8 47 Sand 1667 104.7 132.4 27.7

5 Dukuduku E. grandis x E. camaldulensis

954 21.6 24 Sand 1667 43.7 83.4 39.8

6a Dumbe E. dunnii 874 17.7 1039 Granite 1667 90.2 114.6 23.7

8 Iswepe

E. grandis x E. nitens

876 15.1 1448 Granite 1667 74.3 113.1 38.9

9 Babanango E. grandis x E. nitens

812 18.2 921 Shale 1333 120.4 149.2 28.7

10 Melmoth E. grandis 967 17.6 82 Sandstone 1333 68.4 97.4 29

11 Howick E. grandis 1339 17.2 1000 Shale 1667 78.9 106.2 27.3

12 Paulpieters-burg

E. grandis x E. nitens 874 16.3 1326 Shale 1351 74.5 102.3 27.8

13 Ermelo E. nitens 845 14.6 1496 Gabbro 1667 82.6 110.4 27.8

14 Ermelo E. nitens 869 14.6 1600 Granite 1667 84.6 112.4 27.8

15 Howick E. grandis 859 17.8 850 Sandstone 1667 69.8 97.1 27.3

16 Ixopo E. dunnii 720 17.9 850 Tillite 1667 95.8 123.6 27.8 a Lost to fire in November 2010.

Table 2. Fertiliser type and rates applied to the Control, NPK and NPK+ treatments for the Eucalyptus pulpwood mid-rotation fertiliser (MRF) trials.

Nutrient Fertiliser Application rate (kg ha -1) Control NPK NPK+

Nitrogen (N) LAN (28%) 300 no yes yes

Phosphorous (P) Single phosphate (10.5%) 200 no yes yes

Potassium (K) Potassium Chloride (50%) 100 no yes yes

Calcium (Ca) Calcium Nitrate (19%) 140 no no yes

Magnesium (Mg) Magnesium Sulphate (10%) 50 no no yes

Boron (B) Solubor (17%) 5 no no yes

Copper (Cu) Copper sulphate (25.6%) 5 no no yes

Zinc (Zn) Zinc Sulphate (35%) 2 no no yes


Figure 1. Map of the distribution of mid-rotation fertilisation (MRF) eucalypt pulpwood trials in the summer rainfall region of South Africa

Data analysis

• Final basal area (BA) compared using ANOVA (using initial BA as co-variate)

• LSD (5%) used to investigate differences between treatment means for the different treatments

across all sites

• Basal area growth and relative BA (to control treatments) growth gains assessed

• Relationship between BA increment and site properties investigated

• Cost to benefit determined based on estimated volumes (Assumptions: timber value = R 500 ton-1,

NPK cost = R 14 628 ha-1, NPK+ cost = R 24 483 ha-1, felling cost = R 100 ton-1; contribution

margin = R 400 ton-1, discount rate = 10%)

Results

• No overall significant differences between treatment means, though some significant differences

were found at a few sites (MRF 5, 11 and 13) (Table 4 );

o MRF 5 and 13: NPK+ significantly > NPK and Con,

o MRF 11: NPK significantly > NPK+ and Con.

• Some sites had large differences in initial BA between treatments and the use of initial BA as co-

variate was highly significant (p < 0.001) (i.e. starting BA was an important factor in the growth

response) (Table 4).


• Generally no strongly divergent responses in BA growth curves after fertiliser application were

observed (Figure 3a and b ) (i.e. growth curves between treatments have similar shape at each

site).

• Generally positive responses to fertilisation (relative to the control) were found, but typically these

were not large (Figure 3a and b and Table 5).

• In many cases the response to NPK and NPK+ was inconsistent at some sites (i.e. MRF 5, 8, 11,

13 and 14) (Table 5 ).

• No clear relationship between growth response to fertiliser and measured site properties.

• Cost to benefit analysis indicated that net present value is negative for all treatments at all sites

and that break-even was never achieved.

Conclusions

• Results suggest no significant growth or economic benefit to fertilisation at these sites.

• No clear patterns in responses were found so it is difficult to infer which sites may consistently

benefit from fertiliser application.

• The evidence suggests that it is not currently feasible to increase productivity by economical

measures, through mid-rotation fertilisation of pulpwood stands

• The trial design may have limited the ability to adequately describe patterns of response

(insufficient representation of site classes)

References

Germishuizen I. 2007. A review of the current knowledge of the effects of re-fertilisation on the growth of

eucalypts. ICFR Bulletin Series 09/2007. Institute for Commercial Forestry Research,

Pietermaritzburg, South Africa.

Titshall LW, Rietz DN and Dovey SB. 2012. A general review of site and management factors affecting

long-term site productivity of commercial forestry plantations. ICFR Bulletin Series 07/2012. Institute

for Commercial Forestry Research, Pietermaritzburg, South Africa.

Project technical team

Greg Fuller, Michael Buthelezi, Nkosinathi Kaptein, Denis Oscroft, Musa Mkwananzi,

Acknowledgements

We would like to thank the many companies, foresters and managers, contractors and landowners for

making land available for these trials and with the assistance in establishing them. We also would like to

thank Colin Smith, Ilaria Germishuizen and Alison Archibald for initiating and/or managing the early

phases of trial work.


20

22

24

26

28

30

32

34

0 6 12 20 28

MRF 1

27

28

29

30

31

0 6 11 17 23 27

MRF 2

16

17

18

19

20

21

0 6 12 20 28

MRF 4

18

20

22

24

26

28

0 6 12 20 28 35 40

MRF 5

Bas

al a

rea

(m2 h

a-1)

14

16

18

20

22

24

26

0 5 15 22 28 33 39

MRF 8

16

18

20

22

24

0 8 16 24

MRF 6

16

18

20

22

24

0 8 17 24 29

MRF 9

Con

NPK

NPK+

Months since fertilisation

Figure 3a. Cumulative basal area growth from the time of fertilisation to the final measurement for

mid-rotation fertiliser sites (MRF) 1 to 9 under Eucalyptus pulpwood rotations in South Africa.

24

26

28

30

32

0 6 11 17 23 27

MRF 3


19

20

21

22

23

24

0 5 11 17 22 28

MRF 16

Con

NPK

NPK+

14

16

18

20

0 8 17 24 29

MRF 10

27

29

31

33

35

37

39

41

43

0 5 10 16 22 27

MRF 11

20

22

24

26

28

30

0 3 11 17 22 28

MRF 12

16

18

20

22

24

0 3 11 17 22 28

MRF 13

17

19

21

23

25

27

0 3 11 17 22 28

MRF 14

18

20

22

24

26

28

0 5 10 16 22 27

MRF 15

Months since fertilisation

Bas

al a

rea

(m2 h

a-1)

Figure 3b. Cumulative basal area growth from the time of fertilisation to the final measurement for

sites MRF 10 to 16.


Table 4. Mean (n=2) final basal area and covariate adjusted final mean, basal area for each fertiliser treatment for the eucalypt pulpwood mid-rotation fertiliser trials in South Africa. Fertiliser treatments were the application of no fertiliser (Con) N, P and K (NPK) and N, P, K and micronutrients (NPK+). Statistical comparisons were carried out on adjusted means. Letters that are different indicate a significant difference between adjusted mean final basal area for each treatment across sites (denoted in shaded blocks; LSD5% = 1.2). Bolded text indicate sites where significant differences between the treatments within a site were found.

Con NPK NPK+

Site Actual Adjusted LSD 5% Actual Adjusted LSD 5% Actual Adjusted LSD 5%

m2 ha-1 m2 ha-1 m2 ha-1 1 32.1 26.4 ijklmno 31.4 27.3 nopq 32.5 27.4 opq

2 30.0 23.1 abcd 30.4 22.8 ab 30.6 22.9 abc

3 29.0 23.8 abcde 30.9 23.7 abcde 29.5 24.0 bcdef

4 20.4 22.7 a 18.1 23.4 abcd 19.3 23.1 abcd

5 26.4 26.1 ghijklmn 25.4 25.7 ghijkl 24.0 27.2 nop q

6 21.5 24.1 cde 23.6 25.0 efg 20.3 25.2 fghi

8 20.8 26.7 klmopq 23.8 26.9 lmnopq 20.9 27.1 nopq

9 22.6 26.4 ijkmnop 23.8 27.0 mnopq 23.7 26.7 klmnopq

10 18.4 25.1 fgh 18.2 25.4 ghij 19.8 25.2 fghi

11 35.9 25.8 ghijklm 41.1 26.9 mnopq 34.7 25.4 ghijk

12 27.2 27.6 pq 28.8 27.9 q 28.4 27.9 q

13 22.0 25.2 fghi 20.3 25.7 ghijkl 23.5 26.8 lmnopq

14 26.5 27.0 mnopq 26.1 27.5 opq 24.7 26.7 klmnopq

15 26.6 26.4 hijklmno 26.1 26.5 jklmnopq 25.4 27.1 nopq

16 22.1 23.4 abcd 22.7 24.2 def 23.0 24.0 bcdef

Table 5. The total mean (n=2) basal area increase and annualised basal area increase

(m2 ha-1 yr-1) calculated from the time of fertilisation to rotation end and the difference from the control treatment for each fertiliser treatment for the eucalypt pulpwood mid-rotation fertiliser trials in South Africa. Fertiliser treatments were the application of no fertiliser (Con) N, P and K (NPK) and N, P, K and micronutrients (NPK+). The change (difference) in BA of the fertilised treatment relative to that of the control is also given. The period of time from fertilisation to final measurement is given for reference.

MRF site

Growth period Total increment Annualised total increment

Relative increment

NPK NPK+

Months Con NPK NPK+ Con NPK NPK+ Total Annualised Total An nualised

m2 ha-1 m2 ha-1 yr -1 m2 ha-1 m2 ha-1 yr -1 m2 ha-1 m2 ha-1 yr -1

1 27.7 6.0 6.7 6.9 2.6 2.9 3.0 0.70 0.30 0.92 0.40

2 27 2.8 2.6 2.8 1.3 1.2 1.2 -0.20 -0.09 -0.07 -0.03

3 27 3.3 3.5 3.6 1.5 1.6 1.6 0.24 0.11 0.26 0.12

4 27.7 1.1 1.4 1.3 0.5 0.6 0.5 0.26 0.11 0.13 0.06

5 39.8 4.9 4.4 5.4 1.5 1.3 1.6 -0.50 -0.15 0.55 0.17

6 23.7 2.4 3.5 3.2 1.2 1.8 1.6 1.05 0.53 0.78 0.39

8 38.9 5.2 6.2 5.4 1.6 1.9 1.7 1.00 0.31 0.14 0.04

9 28.7 4.6 5.3 5.0 1.9 2.2 2.1 0.68 0.28 0.34 0.14

10 29 2.9 3.1 3.1 1.2 1.3 1.3 0.20 0.08 0.27 0.11

11 27.3 6.0 7.8 5.6 2.7 3.4 2.4 1.71 0.75 -0.49 -0.22

12 27.8 6.3 6.7 6.7 2.7 2.9 2.9 0.44 0.19 0.39 0.17

13 27.8 3.5 3.6 5.0 1.5 1.6 2.2 0.12 0.05 1.52 0.66

14 27.8 5.7 6.0 5.1 2.5 2.6 2.2 0.34 0.15 -0.58 -0.25

15 27.3 5.1 5.2 5.6 2.3 2.3 2.5 0.05 0.02 0.48 0.21

16 27.8 2.0 2.7 2.6 0.9 1.2 1.1 0.67 0.29 0.61 0.26


A web-based microclimatic measurement and evaporative cooling control

system for shade-netted forestry nurseries

Nkosinathi Kaptein


Introduction

Protected environment structures such as greenhouses and shade-netting are options to reduce the

impacts of many weather hazards and improve control of the microclimate for plant and seedling

production. However, high air temperatures are still frequently experienced under these structures.

Evaporative cooling may be an option to reduce air temperatures within these structures. In this study,

using a web-based data and information system for sharing of measurements and display of the shade-

net environmental conditions in near real-time, the effectiveness of an automated and environmentally-

controlled evaporative cooling system is investigated on the growth of Eucalyptus dunnii seedlings under

a semi-open shade-netting structure.

Material and Methods

Air temperature, atmospheric vapour pressure, solar irradiance, wind speed and leaf wetness duration,

measured using a dielectric leaf wetness sensor, were measured every 2 and 60 min (from 01 January

2012 to 31 December 2012). A data logger was programmed to control evaporative cooling using a

solenoid valve linked to the irrigation system that switched on or off based on the measured shade-netting

micro-climate and leaf wetness. The measured near real-time data was displayed using a web-based

system. The data could be viewed or downloaded using the Internet:

http://agromet.ukzn.ac.za:5355/?command=RTMC&screen=ICFR_nursery.

The automated evaporative cooling system was compared to timer-based system within the shade-

netting structure.

Results and Discussion

The automated evaporative cooling (AEC) system was effective at reducing air temperature inside the

shade-net. Water savings were also found using this system compared to timer-based system. However,

the AEC system over- and under-irrigated at high and low air temperatures respectively. AEC plants

showed poor growth early in the season due to system setup. Seedling growth improved latter in the

season once the AEC system was fully operational. The study showed that AEC can be used with

success in evaporatively cooling the seedlings.

Conclusions

The results from the investigation indicate that the use of an AEC system is effective at reducing

excessively high air temperature under shade-netting. Further benefits include saving of water over a

timer based system. Further refinements are needed to overcome over and under-irrigation problems.


Acknowledgements

Assistance from ICFR staff; Mr Ian Gordon, Drs Steven Dovey, Louis Titshall and Marnie Light and Mr

Robin Gardner is gratefully acknowledged as is the role of Ms Z Ngubane and Mr G Dewar in

constructing the solenoid controller. Funding from the ICFR is acknowledged. UKZN Teaching and

Learning Office funded the web-based system.


The land reform process: Government’s proposal

Roger Godsmark

[email protected] Forestry South Africa, P.O. Box 13735, Cascades, Pietermaritzburg, 3202

Summary

The land issue in South Africa is a highly emotive one. There is no disagreement that the wrongs of the

past need to be addressed – the question is, how?

Since the advent of democracy, the Government has been trying to find solutions to this question and in

this regard has adopted various policies and strategies to meet its target of transferring 30% of “white”

owned land to blacks by a set target date (which keeps changing and is now 2025). Although

Government would like to lay the blame for its failure to meet the various targets set primarily on the

failure of the market system (read as the “willing buyer, willing seller” model), in reality this is far from the

truth. Corruption, incompetence and above all, the failure of the State to provide new beneficiaries with

adequate technical support and sufficient working capital have, in large part, led to this situation.

In respect of the processes followed, I believe that there have been two broad phases in the land reform

process since inception, namely;

1. Phase 1: “Numbers Game”: characterised by Government forging ahead with land reform at all

costs irrespective of damage done (focus: hectares transferred the measure of success).

2. Phase 2: “Pragmatic Game”: characterised by Government realisation that the previous

situation could not continue (focus: sustainability of projects measure of success)

Considering the fact that an estimated 70% of the total afforested area was under claim, FSA, in

recognition of the fact that sustainability was the key to success, developed various “land reform models”

for both corporate and private growers. These models, based on either “lease back” or “management”

models have been accepted by the Department. This occurred during “Phase 1”.

What is encouraging to note is that in 2009, the Department, under the new leadership of Minister

Nkwinti, took note of the concerns that Organised Agriculture (including FSA) had been raising over a

number of years concerning the on-going land reform process and the threat that it posed to food and

fibre security. Most importantly, the Minister, in realising that the Government had dug itself into a huge

land reform “hole”, from which it could not easily escape, enlisted the help of organised agriculture to help

solve the problems. This prompted the Minister to change tack.

Government’s new thinking was contained in the long-awaited Green Paper on Land Reform which was

eventually published on 26 August 2011. This was a far cry from the original draft (126 pages) which had

been long on rhetoric and promises, but short on proposals on how to solve the situation. The new Green

Paper, which contained a mere 12 pages (of which only 2 were rhetoric), was seen by Industry as a “cry


for help”. The Minister’s new approach resulted in a radical policy shift. All funding for new land restitution

deals was halted and any available funding was re-directed to “re-capitalising” those already transferred.

All new projects were to have “strategic” partners. This is what I call “Phase 2”.

This new approach also manifested itself in the establishment of the National Agricultural Reference

Group (NAREG) process. Initially six (but later expanded to 11) Working Groups were established in

which organised agriculture (including FSA) and others were participants. The original Working Groups,

which are still deliberating the issues allocated to them, are as follows:

• Land Management Commission

• Land Rights Management Board

• Valuer-General

• Three Tier System of Land Ownership

• Communal Land Tenure

• Legislative Amendments

Part-way through the process, an additional 5 Working Groups were established to investigate and make

recommendations on the following:

• State Owned and Public Land

• Limitations on Private Land Ownership

• Limitations on Foreign Owned Land

• Rural Financing

• “Project 2013”

Following concerns raised that some of the proposals made in the above Working Groups could be un-

constitutional, the Minister established an “ad hoc” Legal Committee to look into these concerns.

The waters have been further muddied by the gazetting of an “Expropriation Bill” and the stated intention

of Government to re-open the claim claims process to those (a) dispossessed of land prior to 1913 and

(b) who missed the 31 December 1998 cut-off date for lodging claims. The intention to scrap the “willing

buyer - willing seller” system of land purchase has also been proposed.

Deliberations on the issues covered within the ambit of the above Working Groups are still ongoing, as is

the public participation process in terms of the Expropriation Bill. Some issues are highly contentious and

probably unconstitutional and will thus have to be challenged. It is therefore not known at this stage what

will eventually become law. What we do know, however, is that the land environment within which the

Forestry Industry operates will change irrevocably.

This will result in new challenges. What we as an Industry must ensure is that the inevitable changes that

will happen are managed in such a way that the long-term sustainability of the Forestry Industry and as

consequence, the Forest Products Industry to which we supply with raw material, is secured.


Mondi’s Seed Extraction Facility and Research Nursery

Marius du Plessis

[email protected] Mondi, P.O. Box 39, Pietermaritzburg, 3209

Research Nursery

The research nursery which is situated on the hills of the Mountain Home farm was designed from leading

class technology available at the time, constructed during 2010 and commissioned in 2011. The purpose

of the nursery is twofold:

i. To produce quality research plants for the Cold Tolerant Eucalyptus (CTE) programme and the

Pine breeding programme; and

ii. To test latest and class leading technologies in forestry propagation programmes.

To this end, the tunnel technology was sourced from the Netherlands, for obvious reasons, shipped from

The Hague to Durban and erected on site. A few characteristics of this full environmentally controlled

nursery are the following

i. A high roof with large air volume, the reason is to form an effective buffer against sudden weather

changes, preventing the air from rapidly cooling or warming during such events;

ii. The inside temperature is controlled by automated paraffin heaters to keep the inside

temperatures above 15°C;

iii. The roof is a double ridge ventilation design that opens and closes along the length of the tunnels

to allow for rapid cooling when required; and

iv. A retractable screen-system in the roof with 50% shade and a 20% energy saving value.

The sand-bed system was locally designed and manufactured based on similar systems evaluated from

Brazil and Colombia. The beds are filled with 19 mm stone in the drainage area, covered with a weed mat

and filled with Umgeni washed river sand. Water is supplied through a drip fertigation system that is

controlled by a Priva irrigation computer. The 1% slope of the greenhouse allows for drainage of used

water and surplus nutrients, after which is collected in tanks and used over lawns, etc. Strict monitoring is

done to ensure optimum nutrient utilisation.

In the rooting house, under floor heating (maintaining the root zone temperatures between 26-28˚C) is

installed in the green house with heated water supplied from large buffered heat pumps. Misting regimes

is designed to cool off leaves and to generally maintain a high humidity environment. Outside, the nursery

has three bays of varying shade coverage to allow for effective growing out and hardening off of trial

plants.

The sand-bed system is now accepted as benchmark technology for mini-cuttings and will be installed in

Mondi’s commercial nurseries. To date, the nursery has proven to achieve significantly higher rooting

percentages and producing plants of high quality when compared with older macro-cuttings systems


which made use of fan and wet wall systems to control the environment. This adds to the overall energy

efficient design of the nursery which has shown significantly lower electricity costs that any other previous

nursery system.

Seedex

The seed extraction facility was specified to use leading class technology and equipment. The cone and

seed handling equipment was purchased from BCC, Sweden, shipped to South Africa and erected on-site

at Mountain Home.

To follow on the low energy consumption of the nursery, the drying kiln was sourced locally; it has a

heated floor and heated walls warmed with water supplied by a buffered heat pump. The operating

temperature of 55°C is quickly achieved from start- up and effectively maintained throughout the drying

process. No emission or waste is generated from the drying adding to an environment friendly process.

The equipment installed comprise,

i. A tumbler which serves two purposes, that of a seed extractor and wet dewinger;

ii. A seed cleaner and seed sizer (4 screens) where pre-cleaning (scalping) of smaller cones,

extraction of light impurities, removal of debris both larger and smaller than the seed lot and

dividing the seed lot into different sized fractions is done; and finally

iii. A gravity separator. After cleaning and sizing of the seed lot, empty and partially developed seed

is separated from fully developed seed. Final cleaning is also done in this process, removing light

impurities and dust from the seed lot.

The use of the equipment has led to new understandings of genetic representivity by seed family and

seed size classes. It is now possible for Mondi to optimise the seedling crop for uniformity in germination,

for seedlings and for the tree crop. Non-productive seed orchards or individual canopies are removed

from the seed crop to enable optimisation of forest tree seed.

We are very proud of our new facilities; we hope they will have a marked effect in sustained quality

improvement.

Enjoy your visit.

Dr. Marius du Plessis

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