Nouri, M. & Boroomand Nasab, S. Proc. Int. Soc. Sugar Cane Technol., Vol. 28, 2013 ______________________________________________________________________________________

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EFFECT OF FURROW SHAPE ON WATER-APPLICATION EFFICIENCY AND WATER-USE EFFICIENCY IN IRANIAN SUGARCANE

By

M. NOURI1 and S. BOROOMAND NASAB2

1Soil and Water Section, Agricultural Research Department, Karun Agro Industrial Inc, Sushtar, Iran

2Irrigation Department, Shahid Chamran University, Ahvaz, Iran mansourn2001@yahoo.com

KEYWORDS: Sugarcane, Water-Application Efficiency, Water-Use Efficiency, Deep Percolation, Furrow Irrigation, Furrow Shape.

Abstract SUGARCANE IN THE Khuzestan province of Iran is irrigated by furrow irrigation and the crop has a high water consumption, especially during the growth season. This project evaluated the effectiveness of different furrow shapes on water-application efficiency and water-use efficiency (kg yield/m3 water) of sugarcane in fields at Karun Agro-Industry, Inc. Three furrow depths, 30 cm, 22 cm and 16 cm with average water-path profiles of 1370, 1195 and, 562 cm2, respectively, were compared. The total amounts of water used during May, June and July were determined. Results showed an application efficiency in the 30 cm furrows of an average of 71.2%, in the 22 cm furrows of 63.7%, and in the 16 cm furrows of 80.5%. The lowest deep percolation rate, 19.5%, occurred in the 16 cm furrows. Sugar yield did not show any significant difference among the three treatments. We conclude that furrows of 16 cm have the highest water-application efficiency and water-use efficiency.

Introduction Iran is a dry to semi-dry country with low levels of rain and poor distribution of rain across

time and space. Like many countries, it is facing increasing demand for water due to population growth and economic development. The Iranian sugar industry is no exception. We sought to determine the effect of furrow shape on irrigation efficiency and water-use efficiency of sugarcane grown on farms of Karun Agro Industrial Inc. located in Khuzestan province. We aimed to identify an optimal furrow shape for sugarcane cultivation by measuring efficiencies of water application and water use in furrows of different shapes.

Raine and Bakker (1995) showed that water-application efficiency on soils with high infiltration in Australia's Burdekin Delta sugar industry is generally low, on average 30%. However, in soils with low infiltration, it is more than 80%.

By changing the shape of the furrow and also by surface compaction, they could reduce water consumption by 47% with no reduction in crop yield. In a later report, Raine and Shannon (1996) changed the furrow shape from U-shape to V-shape and showed that there was a significant improvement in water consumption. This improvement was due to a smaller wetted perimeter for the V-shape furrows, reducing the advance time of the water from 13 hours in the U-shaped furrows to 8 hours in the V-shaped furrows.

Kashkoli et al. (2000) measured application efficiencies of 5269% on two sugarcane farms of the Haft Tapeh company in Iran with clay-loam soil. Likewise, Malohi et al. (2006) measured water application efficiencies on reshaped furrows (4875%, average 62%) and where furrows were not reshaped (4363%, average 53%) on a farm of the AmirKabir Company.

Nouri, M. & Boroomand Nasab, S. Proc. Int. Soc. Sugar Cane Technol., Vol. 28, 2013 ______________________________________________________________________________________

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Materials and methods We chose an experimental block that had a clay-loam soil. After the first land preparation

operation, three furrow types were constructed: A type with a depth of 37 cm; B type with a depth of 30 cm; C type with a depth of 23 cm. Depths are before planting and corresponded to planting depths of 30, 22 and 16 cm,

respectively. Each treatment was replicated three times in six furrows over 250 m row length in a randomised complete-block design. Measurements were made on three furrows of each of the six. Irrigation efficiencies were measured for May, June and July.

Irrigation was by a gated pipes irrigation system. WSC flumes types 2 and 3 were used in the middle and at the beginning of the furrows to control the discharge of the inlet to the furrows. Infiltration equations were used and the advance time was measured for each experimental furrow at the beginning, middle and end of each furrow. A profile meter (Figure 1) measured the shape of the furrow. The inlet water was 2.5 L/sec, and was controlled by the WSC flume type 3. We recorded the time the water flow was cut off and the times that water disappeared around each of the stations in the furrows.

The Kastiakov-Louis equation ( tfAtz om += ) was used to define infiltration parameters by

the two-point method. The parameters for this equation were calculated by SPSS software. To determine the efficiency of irrigation we applied the equations (Alizadeh, 2005):

%100100

100)(

100))((

0

0

=

=

=

=

ErDPRETWR

tcoQLZV

DPR

tcoQLZ

E

a

reqz

reqa

Where aE is application efficiency, DPR is deep percolation ratio, TWR is tail water ratio (at the end of the furrow when blocked it was 0) and RE = water requirement efficiency = 100%. In these equations reqZ = deep water requirement, L = length of furrow, 0Q = inflow discharge, tco = time of cut off and ZV = total volume of deep percolation.

Fig. 1Profile meter for measuring the area of the furrow.

Nouri, M. & Boroomand Nasab, S. Proc. Int. Soc. Sugar Cane Technol., Vol. 28, 2013 ______________________________________________________________________________________

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Results and discussion The average water path profile in the A furrow was 1370 cm2, 1195 cm2 in B furrows, and

562 cm2 in C furrows, with wetted perimeters of 127, 141 and 78 cm, respectively. Average water-application efficiencies over all the irrigation rounds were higher in C

furrows than in A and B furrows (Table 1), leading to higher yields and water-use efficiencies (Table 2). This is mainly because the wetted perimeter in a C furrow is shorter than in A and B furrows, causing a lower advance time.

In addition, the low volume of surface storage in the C furrow causes a lower recession time for water in this furrow and lowers the deep percolation caused by minimising infiltration over time. The low irrigation efficiency in B furrows is caused by the enlargement of the wetted perimeter of this furrow compared with the other furrows.

Table 1Irrigation efficiencies in treatments with different furrow shapes.

Furrow type

Deep percolation

(m3)

Applied water (m3)

Water requirement

(m3)

Deep percolation

ratio (%)

Application efficiency (%)

A 10.73 37.23 26.50 28.8 71.2

B 15.51 42.67 27.16 36.3 63.7

C 6.53 33.38 26.85 19.5 80.5

Table 2Water use, sugar yield and water-use efficiency with different furrow shapes

Furrow type

Water used (m3/ha)

Sugar yield (t/ha)

Water-use efficiency (kg/m3)

A 24120 16.32 0.67

B 28196 15.86 0.56

C 22023 17.06 0.77

The highest deep percolation in the B and C furrows was at the beginning, and the lowest

deep percolation was at the end of the furrows. The reason for the higher deep percolation was the longer time for infiltration at the beginning of these furrows.

The highest deep percolation in the A furrows was at the end of the furrow; this is because of an increased recession time at the end of this type of furrow, and because of accumulation of water at the end of the furrow, the blocked end and the large volume surface storage in the furrow.

Overall results for the A furrows are similar to those of Kashkoli et al. (2000) who measured application efficiencies in ratoon and plant crops of 52% and 69%, respectively.

The differences in efficiencies among furrow shapes is similar to differences found by Raine and Bakker (1995) who changed from U-shaped to V-shaped furrows. V-shaped furrows had a shorter wetted perimeter that reduced the irrigation times from 13 hours to 8 hours, respectively.

Conclusions Our results show that C furrows are the best shape of furrow for growing sugarcane in

Khuzestan province because, with a lower consumption of water, we achieved a higher application efficiency with no reduction in sugarcane yield.

REFERENCES Alizadeh, A. (2005). Irrigation Systems Design. 6th Edition. Ferdowsi University of Mashhad,

Mashhad, 300311. Kashkoli, H.A., Boroomand Nassab, S., Maroofpour, A. and Andam, M. (2000). Evaluation of

the irrigation efficiencies in sugarcane fields in Haft Tappeh. Agric. Sci. J., 23: 3239.

Nouri, M. & Boroomand Nasab, S. Proc. Int. Soc. Sugar Cane Technol., Vol. 28, 2013 ______________________________________________________________________________________

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Malohi, H., Behzad, M. and Naseri, A.A. (2006). Application efficiencies at two styles of in constructed and unobstructed of furrows in AmirKabir sugarcane fields. Iranian National Drainage Congress, Shahid Chamran University, 819825.

Raine, S.R. and Bakker, D.M. (1995). Increased productivity through better design and management of irrigated canefields. Sugar Research and Development Corporation, Project Number, BS90S. SRDC, Brisbane.

Raine, S.R. and Shannon, E.L. (1996). Improving the efficiency and profitability of furrow irrigation for sugarcane production. In: Sugarcane: Research Towards Efficient and Sustainable Production. J.R. Wilson, D.M. Hogarth, J.A. Campbell and A.L. Garside (Eds). CSIRO, Brisbane, 211212.