Cotton is a potentially important commercial crop and plays a vital role in the textile industry in India. As an irrigated crop it is extensively grown in areas where conventional irrigation methods are commonly used. However, the seed cotton yields and water use efficiency achieved with these methods are very low. In several countries including USA, Australia, Israel, Egypt and others, new irrigation technologies such as drip irrigation have been introduced for cotton.
Implementing drip irrigation to grow cotton not only enables the efficient use of every drop of applied water but also leads to enhanced crop growth and yield advantages. This is due to maintenance of uniform soil moisture regime in the crop root zone by way of frequent irrigations at shorter intervals. Besides irrigation, a major component of profitable cotton production is sound and balanced fertilization. Fertigation i.e., application of fertilizers via irrigation system, ensures the efficient use of nutrients, fertilizer conservation, environmental protection and economics of cotton production. Therefore, an on farm trial was taken up to demonstrate the benefits of drip irrigation in cotton in India.
Fibre and agro-industrial crop Climatic change & water scarcity concerns Increasing fertilizer & labour costs Leaching and washing away of nutrients by runoff Low water & fertilizer use efficiency Low seed cotton productivity/ha Favourable cotton prices
Need for drip
Economic importance of cotton in meeting fibre for textile industry and employment generation To conserve water, increase water & fertilizer use efficiency and optimize cotton yields
Name of the grower
T. Lawrance Reddy
Location: Yaswanthapur, Jangaon (17° 43′ 0″ N-latitude, 79° 10′ 60″ E-longitude), Warangal district, Andhra Pradesh State, India
Area: 1.0 ha
Crop varieties: MCH 12 (Boll Guard)
Crop spacing: Row to row – 1.5 m and Plant to plant – 0.75 m
Seed rate: 1.5 kg/ha
Plant population: 8888 plants/ha
Crop season: Sowing June 12, 2004 & November 24, 2004
Climate: Semiarid climate with mild winter and hot summer, Frost free, Maximum temperature: 28.96 – 40.39°C, Minimum temperature: 16.15 – 27.93°C, Mean vapour pressure: 15.24 – 27.33 hPa, Mean wind speed 4.8 – 12.94 km/hour, Mean day length 11.02 – 13.09 hours, Mean sunshine duration 6.15 – 9.57 hours, Total rainfall: 953.04 mm/year, Effective rainfall: 699 mm/year and Reference crop evapotranspiration: 2023.2 mm/year, Moisture availability index -53%, Aridity index 0.47.
Soil physical properties: Clay loam soil texture; soil pH – 7.5 and bulk density – 1.45 g/cm3; Water table below 6 m
Soil chemical properties: Low in nitrogen (7 mg NO3-N/kg soil), medium in phosphorus (12 mg/kg soil) high in potassium (180 mg/kg soil). Soil salinity (EC 1.5 dS/m)
Water source: Bore well
Power source: Electric motor
Agro-solution: What has been done
Surface drip irrigation system: Head control unit, main & sub-main pipes besides Dripline 2016 integral dripline 16 mm diameter, with a lateral spacing of 1.5 m, emitter spacing of 0.4 m and emitter flow rate 2.0 Litres/hour. Each crop row was irrigated with one dripline.
Year of drip system installation: 2004
Agronomic & Technical support: Crop water requirement & irrigation scheduling (depth and frequency of water application; water quality consideration, measurement of applied water) & fertigation scheduling (soil & water analysis, estimation of nutrient dose, selection of fertilizers & compatibility, application skill via drip system, foliar diagnosis for nutrient deficiencies etc); System operation (pressure reading & maintenance, valves operation, measurement of applied water) & maintenance (cleaning of filters, fertilizer tank, acid treatment, chlorination etc).
Training & capacity building: Soil water plant relationships, drip irrigation & fertigation principles, benefits, limitations & utility; water quality & herbicide usage.
Improved seed cotton yield: Conventional flood irrigation – 3.25 tons/ha & Surface drip – increased yield by 84.6% (6.0 tons/ha)
Crop water use: Conventional flood irrigation – 7700 m3/ha (770 mm/ha) & Surface drip – 4500 m3/ha (450 mm/ha)
Water saving by drip over centre pivot sprinkler: 3200 m3/year/ha (41.6%).
Additional area irrigated by saved water: 0.71 ha.
Economic indices: Higher net returns (1372 US$/ha) by surface drip in comparison to conventional flood irrigation (157 US$/ha).
Other benefits: Saving in electricity charges, more number of bolls/plant, improvement in fertilizer use efficiency, management flexibility, less weed growth due to dry areas between crop rows etc
Drip irrigation of cotton in India is proved to be a feasible eco-technological and economically viable technology Use of scarce water resources sustainably to irrigate additional cotton area with water savings Higher productivity and increased income to growers Farmers are willing to expand the drip irrigation to the remaining cotton area. Cotton best management practices – Surface drip Irrigation & Fertigation scheduling
Grow More: 85% higher seed cotton yield
With Less: Water saving 41.6%