Furrow Irrigation with Decreasing Inflow Rate

A mathematical model has been developed to provide the manner in which the inflow stream size at the upstream end of a furrow must be reduced stepwise according to the infiltration characteristics of the soil so as to eliminate runoff losses from the downstream end and keep the deep percolation losses to the minimum. Owing to the high infiltration rate in the beginning the initial stream size may be large and kept constant till water reaches the end of furrow length. The total period of irrigation is divided into equal intervals of advance time. Equation for calculating the factors by which the initial stream size should be multiplied to get inflow rates during subsequent time intervals has been developed. Graphs have been presented for simplifying the calculations. The method of practical application of the analysis is illustrated by an example.