Water Flow in Soil Surface and Subsurface in Alternate Furrow Irrigation and its Comparison with Conventional Furrow Irrigation

Alternate furrow irrigation is one of deficit irrigation methods that is used to increase water use efficiency and can be applied to mitigate water shortage in agricultural lands. The objective of this research is to compare hydraulics of water flow in the alternate and traditional furrow irrigation regimes. Field experiments were conducted for three furrow irrigation regimes، i. e. alternate (AFI)، fixed (FFI) and conventional furrow irrigation (CFI) at Experimental Station of University College of Agriculture and Natural Resources، University of Tehran، Karaj in 2010. The comparisons were done based on three irrigation events. The results indicated that advance times did not differ between AFI، FFI and CFI. However recession times for AFI and FFI were smaller than CFI. Cumulative infiltration in AFI and FFI was higher resulted in lower runoff losses compared to CFI. Irrigation application efficiency in three irrigation events for CFI، FFI and AFI were ranged 33. 3-56. 2، 58. 8-71. 8 and 60. 7-77. 0%، respectively. Infiltration in the every-other furrows did not change in following irrigation events because of more lateral water movement، but infiltration was decreased in the traditional furrows. CFI had more soil water than AFI and FFI. Soil water content in AFI was somewhat more than it in FFI. This study also showed that with simple modification in the traditional furrow irrigation، irrigation operation cost and water consumption would be decreased. Furthermore، the performance of irrigation system can be considerably improved.