Assessment of Variability of Rainfall and Canal Water under Telugu Ganga Project Command in Andhra Pradesh

The present study was conducted to make a detailed assessment of the variability and relationships of rainfall (mm) received, canal water (Mcum) supplied and the yield (kg/ha) of major crops viz., paddy, groundnut, sugarcane, sorghum and cotton crops attained under the Telugu Ganga Project (TGP) command area in Andhra Pradesh during 1997 to 2021. The crop productivity would always be influenced by the water resource available to a crop. Accordingly, linear and quadratic regression models of yield were calibrated to predict the yield of crops through canal water supplied in different years. The regression models were assessed based on the significance of coefficient of determination (R2) and magnitude of prediction error (PE) of the yield over years. The canal water released in different years was found to significantly influence the yield of paddy, groundnut, cotton and sugarcane crops under the TGP command area. The quadratic regression models gave higher and significant values of R2 compared to the linear regression models calibrated for different crops. The predictability of yield was found to be 0.725 under quadratic model compared to 0.605 under linear model for paddy, while it was 0.458 under quadratic model compared to 0.406 under linear model for groundnut. In case of sugarcane, the predictability of yield was found to be 0.488 under quadratic model compared to 0.431 under linear model. The models were found to be useful for prediction of yield of crops through varying levels of canal water released in different years. This will greatly help to efficiently utilize the canal water resources with regard to the quantity and frequency of water to be provided for irrigation of crops. Since the canal water released under TGP command area is highly assured,we recommend that the farmers could efficiently utilize the available canal water by growing less water requiring crops and attain maximum yield and profit by adopting the improved agricultural technologies of different crops grown under the TGP command area.