Water losses from an irrigated soybean field by deep percolation and evapotranspiration

摘要

Soil water flux below the root zone of a soybean crop was measured in the field at Oakes, North Dakota, during the crop season in 1972 for four water treatments. Amounts of 0, 30.6, 38.1, and 47.0 cm of water were applied in addition to the 19.5‐cm rainfall occurring during the growing season to treatments W‐1, W‐2, W‐3, and W‐4, respectively. Specific in situ unsaturated hydraulic conductivity for each plot of the Maddock sandy loam soil and hydraulic gradients measured with tensiometers in the field during the growing season were used to compute the soil water flux. Knowledge of the amount of water applied by irrigation and rainfall, of the water loss to deep percolation, and of the changes in soil water content in the soil profile permitted estimation of evapotranspiration from the soil‐plant systems.This summary and the entire article are available on microfiche. Order as document W‐75‐001 from American Geophysical Union, 1909 K Street, N.W., Washington, D.C. 20006. Payment ($1.00 must