Determination of infiltration rate for every-other furrow irrigation

Surface irrigation, including every-other and ordinary furrow irrigation is used more than pressurized irrigation due to the low cost and energy requirements. However, more precise selection of design parameters for efficient design of surface irrigation is required for higher irrigation efficiency and the accurate prediction of the infiltration rate is of prime importance. Furthermore, the infiltration parameters may be different in ordinary and every-other furrow irrigation in different inflow rates. Therefore, this research was conducted to determine the parameters of Lewis-Kostiakov infiltration equation in ordinary and every-other furrow irrigation with different inflow rates based on the data obtained in the advancing stage (method I) and in both advancing and storage stages (method II). The results indicated that the Lewis-Kostiakov equation should be modified for furrow irrigation with different inflow rates Q by multiplication of Q(gamma) except for the first irrigation in which Q multiplication is not needed. However, the value of exponent gamma is lower when all data from the advancing and storage stages (method II) are used for calculation of the infiltration parameters. It is also concluded that the infiltration parameters for every-other furrow irrigation are higher than those for ordinary furrow irrigation. Furthermore, the data from the advancing and storage stages (method II) are more appropriate for the calculation of infiltration parameters than the data from the advancing stage (method I), due to the fact that in method II, data were calculated from complete furrow irrigation including advancing and storage stages. (C) 2002 Silsoe Research Institute. Published by Elsevier Science Ltd. All rights reserved.