ECONOMICS OF FURROW IRRIGATION UNDER PARTIAL INFILTRATION INFORMATION

The effects of partial infiltration and furrow geometry information on furrow irrigation design and economic return to water were quantified on a single furrow (reference furrow) and field-wide (10-furrow set) basis using a kinematic-wave furrow irrigation model in conjunction with an economic optimization model. A furrow sampled at 10 locations was assumed to represent the actual field condition. Subsamples were randomly drawn from the 10 samples and return to water was maximized. These suboptimal designs were applied to the actual furrows and monetary loss due to lack of information was simulated. The monetary loss was less for furrow irrigation designs having high inflow rates ($0.38/furrow, $17/ha) than for the low inflow rates ($2.27/ furrow, $100/ha). Average loss decreased from $31/ha ($0.71/furrow) to $0/ha in the case of the reference furrow, and from $1.0/furrow ($44/ha) to $0.3/furrow ($13/ha) in the case of the IO-furrow set for the samples sizes of I and 10, respectively.