Infiltration from semi-circular furrows in the field

Abstract

Experiments on a number of field soils have provided data to check the applicability of recently proposed theory on infiltration from semi-circular furrows. Although spatial variability of soil properties was rather high, the theoretical solutions adequately described cumulative infiltration. The effect of gravity on flow, which is dependent on furrow radius and the ratio of hydraulic conductivity to sorptivity, is not necessarily greatest in soils of high hydraulic conductivity. In most soils gravity effects were pronounced. Qualitative agreement was found between the observed advance of wet fronts and those the theory predicts. Steeper moisture gradients exist near the furrow than would occur near the surface during one-dimensional flow in the same soil. Some factors of relevance to furrow irrigation, and estimation of final infiltration rates from 'short furrow' tests, are discussed.