Infiltration Evaluation Strategy for Border Irrigation Management

Abstract

Water infiltration into soil plays a vital role in the performance of surface irrigation. Real-time information on infiltration characteristics is necessary to use surface irrigation models to manage irrigation systems. The present field study deals with the evaluation of the Kostiakov infiltration parameters using water front advance information at three different locations (50, 75, and 100% of the field length) along the alfalfa irrigated borders. Two irrigations were conducted on four border checks. The parameters of the Kostiakov infiltration model were determined using the one-point and two-point methods for these locations. The infiltration parameters for each border were used in a surface irrigation model to evaluate their impact on irrigation performance measures. The mean irrigation performance measures, such as inflow volume, application efficiency, tailwater ratio, deep percolation ratio, and low quarter distribution uniformity, were significantly different for one-point and two-point methods. However, the mean performance measures were not significantly different for infiltration functions evaluated at three different locations using the two-point method. Furthermore, performance of individual irrigation events was in close agreement for all three locations. Thus, infiltration parameters can be estimated using the water front advance information up to 75% of the field length (to reduce the impact of soil spatial variability) and can be used to predict irrigation performance measures reasonably well. A cutoff strategy that ensures the advancement of the wetting front to the downstream end of the field was devised on the basis of the infiltration parameters evaluated at 75% of the field length. This cutoff strategy resulted in savings of applied water (18%) and reduction in both tailwater and deep percolation losses, which gave higher application efficiency. The methodology presented in this article has the potential for use in real-time management of border irrigation systems.