Evaluation of irrigation water productivity and economic analysis of alfalfa production in sprinkler and surface irrigation systems.

Recent droughts and limitation of water resources have required Proper use of water, measurement and analysis of water productivity indices in different irrigation (surface and pressurized irrigation systems) methods. So this project was conducted to evaluate irrigation water productivity and economic analysis of alfalfa crop production in Hamedan- Bahr plain. In order to 16 alfalfa farms which had sprinkler and surface irrigation were selected and examined. Volume of water consumed was calculated by measuring the water discharge (using Flume method or Water Meter), sprinkler discharge, irrigation hours per irrigation and total number of irrigation. Economic analysis of the alfalfa production was carried out by using the present value of net benefit, Benefit cost ratio and Economic productivity of water with consideration of government grants and regardless of government assistance in the sprinkler irrigation system and surface Irrigation. The average amount of water consumed and water productivity in surface and sprinkler irrigation were estimated 12447 and 7875 cubic meters per hectare and 1.6 and 2.7 kg.m-3 respectively. In this way, the sprinkler irrigation system with a 37% reduction in water consumption has increased the water productivity by 69%. In this way, the sprinkler irrigation system with a 37% reduction in water consumption has increased the water productivity by 69%. The results of economic analysis showed that the present value of the net benefits of alfalfa cultivation in sprinkler irrigation system relative surface irrigation is more than about 74437 thousand rials with government assistance grants. The benefit-cost ratio in sprinkler irrigation systems is 3.8 and 3.2 with or without government subsidies respectively