Conservation of Surface and Ground Water

Streams, canals and wells irrigate only about 15% of the total agricultural land in Karnataka. Farmers in 85% of the cultivated land depend entirely on rainfall. Droughts being a frequent phenomenon, a need to develop measures to conserve both surface and subsurface water was felt.

During the year 1985-86 the surface water conservation aspect was studies with reference to dry land agriculture. The study was conducted at 'Ungra' village using a farm pond. This pond was dug to ensure supply of water to rainfed crops at crucial stages of growth. A comparison between yields of ragi gram in these plots and in those which depended on rain alone, revealed that the grain and straw yield was more, by 60 to 80 percent irrespectively in the irrigated plots. Allowing for the cost of excavation of pond, the loss of crop revenue from the area occupied by the pond, and ignoring the fodder value of the increased straw yield, the net benefit was the order of Rs. 300 per hectare. If the seepage and evaporation losses could be reduced, the same pond could
irrigate more area. The project was further pursued on the following two lines:

A. An analytical study on farm ponds as surface water conservation structures, for regular or life saving irrigation, for dry crops was undertaken, and

B. (b) An experimental study on the effect of land treatment on ground water recharge, was also carried out.