Interaction of Slope and Input Flow on Efficiency and Uniformity of WaterDistribution in Furrow Irrigation of Sugarcane

Among the surface irrigation methods, furrow irrigation is the most common and adapted method to mechanization for agricultural system. In this irrigation method longitudinal slope of furrow is uniform and constant. To increase application efficiency, more uniformity of water distribution and reducing runoff and deep percolation, techniques such as wave irrigation and reduced discharge is applied that all need special equipment. In order to investigate the interaction of longitudinal slope and input flow in clay-silt soil texture on the efficiency and uniformity of water distribution in sugarcane furrow irrigation, a split plot experiment was conducted in a randomized complete block design with four replications in summer of 2017 in Salman Farsi agro-industry. The main factor of longitudinal slope was in three levels 0.2, 0.4 and 0.6 (S0.2, S0.4, S0.6) per thousand, and sub factor of input flow in levels 1.5, 2 and 2.5 (Q1.5, Q2, Q2.5) liters per second. The results showed that the interaction of two factors in the index of water advancement time was significant and (Q2.5) treatments was the highest rank in the 3-slope level. Interaction effect in the index of water efficiency was not significant. For the Index of uniformity of water distribution, interaction of two factors was significant. With increasing input flow to Q2.5 (liters/s) at three levels of slope, the highest uniformity of water distribution was obtained 87%, but in other treatments the uniformity of water distribution was higher than acceptable level. At slope (S0.6) and input flow (Q1.5) treatments, the application efficiency and uniformity of water distribution were 85% and 82%, respectively. So S0.6 longitudinal slope and input flow are recommended because of optimal efficiency and uniformity of water distribution in furrow irrigation of sugarcane fields of Ahwaz.