REVIEW OF IRRIGATION WATER MANAGEMENT PRACTICES FOR SUGARCANE CROP Dr. Shahid Afghan Director Research Shakarganj Sugar Research Institute Jhang Punjab Pakistan
H2O FACT SHEET Water content varies 70 90 % Age of plant Plant species particular tissue Environment
Water flow amounts to: 1-10 times water held in plant tissues 10 to 100 times the amount used in expansion of new cells 100 to 1000 times the amount used in photosynthesis
H2O Plant functions Solvent and medium for chemical reactions Medium for organic and inorganic solute transport Medium that gives turgor to plant cell. Turgor promotes cell enlargement, plant structure, and foliar display Raw material for photosynthesis, hydrolytic process, and other chemical reactions in the plant Water evaporation (transpiration) for cooling plant surfaces
Main Constraint of Cane Crop Irrigation is the main constraint affecting yield and quality of sugarcane crop 50-60 % needs of sugarcane crop are met through canal water 240-400 mm annual precip. mm (monsoon) Sub soil water quality (fit or unfit) 10 % under cane in existing cropping pattern
Sugarcane crop Critical stages Requirements inches/ton 40 tons crop Actual need 50 % losses zone Early growth period Grand growth phase Maturity stage 1.25-1.5 acres 50-60 acre inches 100-120 acre inches Surface evaporation Run off Leaching beyond root Transpiration by weeds
Establishing Crop Water Use Field studies Improved Irrigation Technologies Scheduling tools Cultural Practices Soil, Water and Sugarcane The need for irrigation Crop response to irrigation Irrigation Water Quality Water quality and its effect on crop growth Symptoms of water quality problems Improving water penetration
Irrigation System Irrigation Scheduling Impact of management practices on conservation of irrigation water
Types of water quality and corrective measures Water Quality Corrective measures Type-1 Low salinity water EC = 0-6 dsm-1 Poor in light soils Irrigation waters may be mixed or treated with gypsum. Alternatively treat soil with gypsum Type-2 Low salinity Poor on As above water with residual alkali light soils EC = 0-6 dsm-1 Type-3 Average salinity water EC = 0.6-1.5 dsm-1 Good Nil
Water Quality Corrective measures Type-4 Average salinity Good-fair water EC = 0.6-1.5 dsm-1 Light soils may require action as above Type-5 High salinity water EC = 1.5-2.2 dsm-1 Fair-poor Ensure irrigation is heavy enough to prevent salt accumulation in the soil. Type-6 Very high salinity water EC = 2.2-3.2 dsm-1 Very poor Use on sandy soils only. Wet soil to a depth of at least one meter. Type-7 Water Unsuitabl Do not use unsuitable for irrigation e -1 Manual of cane growing, BSES Australia M. Hogarth & P.3.2 Allsopp (2000) EC = over dsm
Readily available water (RAW) for a range of soil types 100 80 60 40 20 0 Readily Available Water (mm) Cracking clay Sandy loam Clay loam Loamy sand Loam Anonymous (1998) Irrigation of sugarcane, SRDC Australia
Soil-Water Relationship Wilting point is reached when water between the soil pores is depleted Field capacity occurs when some soil pores are filled with water Slow, heavy irrigation leaches salts below the root zone
Large hills and narrow interspaces limit water penetration Small hills with broad flat interspaces maximize water intake
Impact of irrigation levels and row spacing on cane yield, drainage and water use efficiency Treatment Irrigation Full Def-1 Def -2 Row spacing Yield (t/ha) CWU (mm) Irrigation Drainage (mm) (mm) WUE (t/100 mm) 0.4 180 1427 1332 190 12.6 0.6 177 1426 1332 190 124 0.9 196 1434 1332 190 13.7 0.4 161 939 687 60 17.2 0.6 170 963 687 60 17.7 0.9 158 939 687 60 16.8 0.4 125 840 551 60 15.0 0.6 142 783 551 60 18.2
Improving Water Penetration Irrigation technique: Small ridges and broad FLAT interspaces Small irrigation outlets and larger watering sets. Slope: Too much slope on a block will reduce the intake of water. Where water penetration is poor, the slope should not exceed 0.125%.
Improving Water Penetration Trash blanket: Improve water penetration Slows the flow of water down the drill Allows more time for the water to infiltrate into the soil. Increased irrigation times up to 25% have been observed. Soil surface is improved and this aids water infiltration. In young ratoon crops, a trash blanket acts as a mulch to reduce evaporative losses from the soil Measurements show that up to 40 mm additional soil moisture can be conserved
Improving Water Penetration Organic material: Mill filter cake, green manure or FYM will improve water penetration when incorporated into the soil. However the effects are only temporary and usually last no more than two seasons. Soil ameliorants: Improved by applying a soluble form of calcium. Gypsum applied at 10 tonnes per hectare is the most suitable product.
A mini pan for measuring evaporation Source: BSES Australia
Effect of minipan deficits on cane and sugar yields Minipan deficit (mm) Cane yield (t/ha) CCS (%) Sugar yield (t/ha) 120 133.9 15.6 20.7 150 104.2 15.6 16.3
Evapo-transpiration ratio and root depth of sugarcane crop during different growth phases Different growth phases Crop duration (months) Evapotranspiration ratio Rooting depth (%) 5 1 100 6-10 1 100 Maturity 11-12 0.7 100 Ripening 13-14 0.4 100 Formative phase (full water use) Grand growth (peak water use) C. A. Jones (1980) Hawaiian Sugar Planters Association, Hawaii
Wetting up pattern from drip irrigator
Drip Tap Irrigation of Sugarcane
Studies on Drip Irrigation Project area = 8 acres Water savings S. crop A. crop 15% 22% Yield t/ac 26 35 Installation cost = 40,000/acre Problems Filter blockage (FeSO4) T-tap cracks Root intrusion
Tensiometer
Some useful hints on Tensiometer Tensiometer should be installed to a depth of 60 cm in the plant line, except in very sandy soils where they should be installed to a depth of 30 cm in the plant line. Tensiometer need to be installed carefully and maintained regularly to ensure they do not run out of water. Two unit per site gives more accuracy.
A view of cane-trash mulched field
Impact of mulching treatments on cane and sugar yield 100 10 1 Cane yield (t/ha) Weeding S.cane trash N. A. Deho (2002) PSJ Sugar yield (t/ha) Wheat straw No weeding
Effect of trash mulch on yield and water use efficiency of sugarcane Mulching Cane Total yield irrigation (t/ha) water (ha. cm.) Water use efficienc y Saving of water (%) No trash mulching 66.5 30.0 2.34 - Trash mulching 79.5 18.7 4.38 36.6 Anonymous (2001) South African Sugar Association Experiment Station, South Africa
A WINCH irrigation system in action
Neutron Hydro-probe
Enviro SCAN logger
Gypsum blocks with electrodes
Enviro SCAN sensors
Cane yield response to irrigation scheduling 1000 100 10 1 Non scheduled (t/ha) Heavy soil Scheduled (t/ha) Medium soil C. Black (1996) Agronomic Society of America USA Production increase (%) Light soil
Sugarcane yield response to irrigation scheduling using evaporation minipan Soil type Variety NonSchedule Producti scheduled d (t/ha) on (t/ha) increase (%) Alluvial Q117 124 136 10 Non Sodic Q117 107 120 12 Q96 88 110 25 Sodic 1R, 2R and 3R refers to first, second and third ratoon crop respectively
Effect of moisture stress Irrigation Cane Coefficients Yield loss 1.00 0.80 0.60 0.40 0.00 11.5 26.5 48.5 % % % %
Response of CPF-237 to various irrigation levels Irrigation applied at Yield t/ha CCS % CPF-237 CP 77400 CPF-237 CP 77400 0.6 Coefficient 64.30 58.20 13.59 12.61 0.8 Coefficient 78.25 77.95 13.41 13.07 1.0 Coefficient 100.40 101.00 13.49 12.93 Average 80.98 79.05 13.50 12.87 Ref: Variety approval case
Response of CPF-234 to various irrigation levels Irrigation applied at Cane yield t/ha CPF-234 CP 77-400 Average 0.6 Coefficient 63.0 64.0 63.5 0.8 Coefficient 77.0 75.0 76.0 1.0 Coefficient 91.0 82.0 86.5 Average 77.0 73.7 Ref: Variety approval case
Irrigation systems Selection of suitable irrigation system depends on: Availability and cost of water Water quality Soil type Soil slope Cost and labour requirement of equipment Expertise needed to operate the system
Irrigation systems Surge irrigation Skip-furrow irrigation Water cannons Hand shift sprinkler Lateral move irrigators Center pivot irrigators Drip irrigation
Cane yield and water saving (%) under different irrigation systems 100 10 1 Cane yield (t/ha) Drip irrigation Water saving Winch irrigation Standard furrow P. Sutherland (2000) Manual of cane growing, BSES, Australia
Furrow shapes play an important role in water infiltration rates
Effect of furrow shape and cultivation practices on irrigation water usage 3.5 3 2.5 2 1.5 1 0.5 0 Reduced cultivation Water usage (ml/ha/irrigation) Broad (U) Conventional cultivation Narrow (V) Anonymous (1998) Irrigation of sugarcane, CSR, Australia
Individual furrow irrigation on a light textured soil
Yield and water use efficiency of sugarcane as affected by methods of irrigation Methods Yield Water of (t/ha use irrigation ) efficienc y Total Saving irrigation of water water (ha. (%) cm.) Flood 66.2 3.02 23.7 - Furrow 64.3 3.00 20.0 15.4 Skip furrow 54.4 4.95 15.0 36.5 G. Ham (2000) Irrigation of sugarcane BSES Australia
Individual furrow irrigation
Surge irrigation system showing surge valve and controller
Effect of furrow length on furrow irrigation efficiencies 100 10 1 0.1 WA (ml/ha) Furrow length 300 m WAE (%) 500 m 700 m G. Kingston (200) Irrigation of sugarcane, SRDC, Australia
Correct tracking by water cannons, on well maintained two paths
Under windy conditions, water cannons give un-even water distribution
Portable hand shift sprinklers in use
Lateral move irrigator
Center pivot irrigator
Low pressure boom irrigation
Summary of irrigation system Irrigation system Furrow Water cannon Handshift sprinklers Lateral move Capital costs Low-medium Medium Medium High Labour High Medium High Low Management Low Medium Low Medium Requirements Land leveling Lanes Nil Lane Efficiency Medium Medium Medium Medium Limitations Slope and soils Wind Wind Speed of operatio n Relative cost Low High Medium Medium Anonymous (2000) Manual of cane growing, BSES, Australia
Summary of irrigation system Irrigation system Center pivot Boom Drip Capital costs High Medium Mediumhigh Labour Low Medium Mediumlow Management Medium Medium High Requirements Suitable slopes Lanes Maintenanc e, filtration Efficiency Medium Medium High Limitations Speed of operation Speed of operation Water quality Relative cost Medium Medium Low Anonymous (2000) Manual of cane growing, BSES, Australia
Practical measures Selection of verity high yielding with high water use efficiency Improve cultural practices to increase water intake and storage Selection of proper irrigation method Improve furrow irrigation management