The effects of improved permeability on rainwater harvesting in irrigated fields

Infiltration phenomenon, has a direct impact on rainwater harvesting in fields under irrigation. In order to solve this problem (reduced infiltration and increased runoff), a few strategies can be suggested. Taking longterm decision for increasing the efficiency of irrigation should be strongly suggested. At the same time, ways in which customized irrigation is optimized must be studied. An old irrigation method has been used in large scale in Iranian furrow irrigation. Different design methods for furrow irrigation are offered; the most important ones are: 1-SCS (Soil Conservation Service) method; 2- FAO method; and 3-walker and Skogerbo method. The present study offers a design method that is suited according to environmental conditions and discusses the results obtained from this study. Attempts were made to identify the efficient length of furrow. A study field in Amirabad farm of college of Agriculture at Birjand University was selected. Preparation and leveling of the field was done, since furrow irrigation of the slope gradient for land leveling is very important. This research focused on soil infiltration (Double ring and input output methods), advance time and recession time, and measuring furrow cross section in different steps during the study. Results showed the possibility of improving water use efficiency using furrow irrigation technique. Finally, it was concluded that using SCS is more consistent with methods of rain water harvesting and on-farm water efficiency.