• Depending upon the agro climatic conditions, type of soil, methods of planting and use of manures and fertilizers and sugarcane yield the water requirement varies.The hot weather associated with dry winds and drought increases the water requirement of the crop. 

• The crop sown in trenches needs relatively less water but sandy soils and application of more fertilizers increase the water uptake.  On an average 1 ton cane needs about 60-70 tons of water or  thin varieties of cane need 150 cm thick canes and need 200 cm water and Adsali planted canes 200 cm, in addition to 75 cm rainfall.  The crop should be irrigated when available water reaches to 50% level.

•  The soil must have sufficient moisture at the time of sowing.  First irrigation should be done when about 20-25% plant have germinated or about 20 days after sowing and the irrigations are given at 10-15 days interval during summer, 25-30 days interval during winter and if there is drought the crop should be irrigated during rainy season also as and when needed.  The crop needs maximum water at tillering stage and during elongation or grand growth phase.

• Under water logging conditions the root respiration becomes poor.  Nutrients are leached down, activities of useful micro-organisms are reduced and the crop lodges down with an excessive branching.  Thus the quality becomes poor along with very low crop yield.  These all make it necessary to drain the excess water from the field.

Growth Phase

Irrigation Interval (days)

Coarse textured soil

Medium textured soil

Fine textured soil

Germination(0-45 days )

5-6

6-7

8-10

Tillering Phase(45-120days )

6-7

7-10

12-15

Grand Growth Phase(120-270days)

7

10

12-15

Ripening Phase(270-360 days)

10

12-15

15-20

Irrigation system

Water applied

(ha -cm)

Cane yield (mt/ha)

Water use efficiency

C. C.S. (mt/ha)

Rain gun sprinkler

175.26

126.56

0.72

17.87

Drip irrigation

132.14

128.64

0.97

18.29

Furrow irrigation

258.45

104.42

0.4

14.71

Alternate skip furrow method:

• In skip-furrow method, sugarcane is planted in flat beds as usual and   after germination, 45 cm wide and 15 cm deep furrows were made in alternate inter row spaces.

• There is considerable saving of water in this method of irrigation.

• In Autumn planting, there are 7 irrigations in plains (5 before rain and 2 after rain)

• In spring planting, there are 6 irrigations (4 before rain and 2 after rain) - one irrigation at tillering is must.

Sprinkler irrigation:

• For sprinkler irrigation, increasing use is made of spray guns, hand and automatically moved, replacing the cumbersome boom and labour-intensive hand-moved sprinkler laterals Prevailing winds of more than 4 or 5 m/sec will limit their usefulness.

Drip irrigation:

• Drip irrigation is defined as the precise, slow and frequent application of water through point or line source emitters on or below the soil surface at a small operating pressure (20-200 kPa) and at a low discharge rate (0.6 to 20 LPH), resulting in partial wetting of the soil surface.

• Drip irrigation is defined as the precise, slow and frequent application of water through point or line source emitters on or below the soil surface at a small operating pressure (20-200 kPa) and at a low discharge rate (0.6 to 20 LPH), resulting in partial wetting of the soil surface.

• Drip irrigation in sugarcane is a relatively new innovative technology that can conserve water, energy and increase profits.

• Drip irrigation may help in solving three most important problems of irrigated sugarcane - water scarcity, rising pumping (energy) costs and depressed farm profits

• Drip will be successful depends on a host of agronomic, engineering and economic factors.

• 12 mm drip laterals have to be placed in the middle ridge of each furrow with the lateral spacing of 240 cm & 8 ‘Lph’ clog free drippers should be placed with a spacing of 75 cm on the lateral lines. The lateral length should not exceed more than 30-40 m.

• Drip Irrigation is given once in three days based on the evapo-transpiration demand of the crop.

Surface Drip:

• The application of water to the soil surface as drops or a tiny stream through emitters placed at predetermined distance along the drip lateral is termed as surface drip irrigation.

• It can be of two types - online or integral type surface drip system. Integral dripline is recommended for sugarcane.

Subsurface Drip (SDI):

• The application of water below the soil surface through emitters molded on the inner wall of the dripline, with discharge rates (1.0 - 3.0 LPH) generally in the same range as integral surface drip irrigation.

• The integral dripline (thin or thick-walled) is installed at some predetermined depth in the soil depending on the soil type and crop requirements.

• There are two main types of SDI - "one crop" and "multicrop".

• Subsurface irrigation saves water and improves yields by eliminating surface water evaporation and reducing the incidence of disease and weeds.

• Save 25-50% of water

• Low requirement of water.

• Evaporation losses get reduce.

• Decrease the number of weeds.

• Period of irrigation is low (2-3 hours)

• The growth of plants is homogeneous.

• Little application of water but gives more yield.

• Decrease the infestation with pests (insects, diseases and weeds).

• Increasing the area of planting by saving the area of canals.

• Decreasing man infection by contacting the water (bilharzia or Schistosomiasis).

• Decreasing the pollution in canals.

There is considerable saving of water in this method of irrigation.

Fertigation

• Sugarcane being a giant crop producing huge quantity of biomass generally demands higher amounts of nutrient elements.

• The cost of chemical fertilizers has also increased and there is a need to improve fertilizer use efficiency for more benefits. The best answer to this challenge is "Fertigation", where both water and fertilizers are delivered to crop simultaneously through a drip irrigation system.

• Fertigation ensures that essential nutrients are supplied precisely at the area of most intensive root activity according to the specific requirements of sugarcane crop and type of soil resulting in higher cane yields and sugar recovery.

Concept of fertigation

• Fertigation is the judicious application of fertilizers by combining with irrigation water.

• Fertigation can be achieved through fertilizer tank, venturi System, Injector Pump, Non-Electric Proportional Liquid Dispenser (NEPLD) and automated system.

• Recommended Nitrogen & Potassium @ of 275 and 112.5 kg/ha  may be applied in 14 equal splits with 15 days interval from 15 DAP.

• 25 kg Nitrogen and 8 kg K2O per ha per split.

• Urea and MOP (white potash) fertilizers can be used as Nitrogen and Potassium sources respectively.

• Fertigation up to 210 DAP can also be recommended.

Requirement & Type of Water soluble fertilizers in Sugarcane
Recommended dose: 275: 62.5:112.5 kg NPK / ha
For Fertigation recommended: 275:15:112.5 NPK / ha

• Distribution of plant nutrients more evenly throughout the wetted root zone resulting in increased nutrient availability & uptake contributing to higher crop growth rates and cane yields

• Supply of nutrients incrementally according to the crop developmental phases throughout the season to meet the actual nutritional requirements of the crop

• Careful regulation and monitoring the supply of nutrients

• Application of nutrients to the soil when crop or soil conditions would otherwise prohibit entry into the field with conventional equipment

• Minimal nutrient losses through consumption by weeds, leaching and runoff

• No damage to the crop by root pruning, breakage of leaves, or bending of leaves, as occurs with conventional fertilizer application methods/equipment

• Less energy is expended in application of the fertilizer

• Usually less labour & equipment are required for application of the fertilizer and to supervise the application

• Soil compaction is avoided because heavy equipment never enters the field

• No salt injury to foliage

• Allows rising of crop on marginal lands, where accurate control of water and nutrient ion in the plant's root environment is critical.