Irrigation potential for optimal cropping pattern in a command area and operational policy

In Indian economy Agriculture has a major role. More than 50% population depends on agriculture for livelihood. It is observed that there is a significant difference in farmer preferences and the notified cropping pattern by the department in most of the command area. There is a mismatch between demand and supply for notified cropping. To bridge the gap between these two, Irrigation potential is highly necessary. In this work, a frame work has been developed to understand the optimal cropping pattern in the command area for maximum yield. For this purpose, Harihar branch canal of Bhadra reservoir situated in Davanagere district, Karnataka, India, was considered. Notified cropping pattern and water supplied through the Harihar branch canal was studied. Depending on water availability in the reservoir, suitable cropping pattern was suggested by entrusting authority in the study area for different seasons. Irrigation water requirement for the notified cropping pattern was calculated for different rotations. It was observed from the computation that there is deficit of water supply during the beginning of season and it is surplus toward the end of the season in some distributaries. This leads to a Rotation policy consisting of 10 days ‘ON’ and 10 days ‘OFF’ system. This indicates, in between the two rotations, one rotation is OFF; therefore, the water requirement for the notified crops during OFF rotation has to be supplied with the water availability during the ON rotation which is more than the full capacity of canal. From this study it was found that, water demand is not satisfied in most of the distributaries after introducing the rotational policy. By understanding the inefficiency of Rotation policy, there is a need for revising the cropping pattern in the system and hence optimal cropping pattern with available resources in the command area is suggested.