RAINFALL DISTRIBUTION PATTERN FOR CROP PLANNING IN RAICHUR REGION (KARNATAKA), INDIAVishwanath, G.V. Venkataramana and N. Prabhakaran
Rainfall during monsoon season and its variability governs the cropping system in the rainfed regions of Raichur. Daily rainfall data of one hundred fourteen years (1913-2020) have been analyzed for establishing the long term averages of monthly, seasonal and annual rainfall and its variability. The overall mean annual rainfall at Raichur region was 672.6 mm with average rainy days of 42 days, and distribution of 486.2 mm, 124.5 mm, 55.9 mm and 6.0 mm in monsoon, post monsoon, summer and winter respectively. The coefficient of variation of 29.8 indicated that rainfall was more or less stable over the years. Monthly rainfall had unimodel peak, September receives maximum mean rainfall of 148.1 mm followed by August (124.8 mm). Within the rainy season, September was the highest rainfall contributing month (22 per cent) followed by August (18.6 per cent). There is an ample scope for rain water harvesting from July to September which can be utilized as crop saving irrigation as well as pre sowing irrigation for succeeding Rabi crops which are generally sown on residual soil moisture. The study also revealed that the rainfall and rainy days during monsoon season ranged from 157.8 to 813.7 mm and 21 to 66 days respectively. According to âNakshatrasâ, the traditional system of rainfall distribution for agriculture, revealed that the period from Punarvasu to Chitta received good amount of rainfall during which crops like groundnut, sunflower, maize, Bajra and pulses like greengram, pigeon pea and chick pea can be taken up.