Determination of infiltration in furrow irrigation system under variable furrow cross section and bed slope

Infiltration is one the most important parameters in surface irrigation which its accurate measurement is obvious. It could potentially affected by different parameters such as bed slope، discharge، cross section and roughness coefficient. In this research، Kostiakov-Louis equation (KLE) was employed using two-point method، in order to measure the soil infiltration rate. This study was carried out in research field of Shahrekord University، Shahrekord، Iran. A completely randomized block design was employed with three treatments and three replications. The effect of changes in furrow bed slope and shape is evaluated on the soil moisture distribution، soil infiltration rate and cumulative infiltration. Statistical analysis was performed using the LSD test. The results show that the lowest infiltration rate (0. 00052 cubic meters per minute) and cumulative infiltration value (0. 5 cubic meters per meter) were observed in variable furrow bed slope. The changes in the slope were significant (P<0. 01) on soil infiltration rate and soil basic infiltration rate (). There is no correlation between cross section variation and KLE parameters including k، a and (P<0. 01). The result shows that soil moisture distribution was more uniform in variable cross sections than other treatments