IRRIGATION WATER MANAGEMENT OF MALLOUR DISTRIBUTARY IN AMBALA

Abstract

Estimation of crop water requirements is essential for irrigation scheduling and optimal water management. In this study, conditions of crop water and irrigation scheduling of Kharif and Rabi seasons are estimated for the command area of Mallour distributary in Ambala at Haryana. Paddy and wheat are the major crops grown in the study area of Ambala region. The duration of the paddy crop is mainly of 120 days, and that of wheat crop is 140 -160 days. The CROPWAT model developed by the Food and Agriculture Organization is used for computing crop water requirements and irrigation scheduling. The meteorological data from 1981 to 2019 were obtained from the Nasa Power Generation, and soil data from FAO 56 paper. The rainfall characteristics are estimated with climatological data, and it is observed that the average annual rainfall is about 773.56 mm, out of which about 630 mm occurs during the monsoon season. The CROPWAT model was used to calculate the reference evapotranspiration (ETo), Evapotranspiration (ETc), and irrigation water requirements (IWR). The results showed that the average seasonal ETc for 2016 to 2019 is 263.70 mm for wheat and 788.60 mm for paddy crop. The lowest monthly ETo (138.43 mm) was in January, and the highest (225.71 mm) in June. The estimated irrigation requirement for paddy and wheat are 291.2mm and 161.6 mm, respectively. Various options for increasing irrigation efficiency are analysed. For example, various varieties of paddy crop viz., 1121, PR 128 and HKR 47 with different cropping periods are analysed for reducing irrigation requirement. The irrigation requirement for paddy crop variety 1121 is estimated as 285.40 mm. Its cropping period is 135 days from 30th Jun to 27th October. The irrigation requirement reduced to 270.4 mm for the PR 128 variety. Moreover, the paddy crop variety HKR 47 transplanted on 5th July and harvested on 12th October saves about 10.30% of irrigation water. A cost analyses was also carried out to check the income of the farmers. It was

observed that the minimum support price (MSP) rate of farmers was not sufficient compared to the actual cost incurred by the farmers. It is therefore suggested that the crop variety be replaced by HKR 47 to save irrigation water, which can be utilized to enhance the irrigation efficiency and increase the crop production area.