Redistribution of soil water after infiltration

Abstract

The redistribution of soil water after the cessation of infiltration in three agricultural soils was analyzed experimentally in the laboratory. It was found that the rate of redistribution within the soil profiles depended upon the initial depth of wetting and the soil water content‐soil water pressure‐capillary conductivity relations. The results are discussed in relation to measured and predicted profiles of inert porous mediums. (Key words: Infiltration;irrigation; soft water)

Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 1: The Southern Colorado Plateau and Rio Grande Regions

“…Also shown in Fig. 4b are data for infiltration of water into clay loam (Biswas et al 1966). Note that increasing sediment permeability (silt loam > clay loam) leads to increased penetration depths at both 0 h and 30 days.…”

“…Extrapolation of the data for front penetration at 0 h and 30 days into the silt loam ( Fig. 4a) indicates that Biswas et al (1966). b Cumulative evaporation of soil water as a function of evaporation rate in a silt loam.…”

“…3a. In this experiment, 6.1 cm of water was applied at controlled pressure to a 100-cm-long column of soil (Biswas et al 1966). The rate of water percolation slows with time, and the water's leading edge can be fit with an equation of the form…”

Simulation-model-derived weather indexes for regressing Iowa corn yields on soil, management, and climatic factors

“…A rationale for the general redistribution procedure can be found in studies by Biswas et al (1966) and Gardner et al (1970). By using three soil types homogeneously packed into columns, Biswas et al The arbitrary decision to wet lower layers to field capacity as restrictive layers were encountered during infiltration or as redistri bution proceeded through the base of an infiltration profile was based on the general concept of field capacity, i.e., the uniform moisture content profile which develops after redistribution reaches the stage at which hydraulic conductivity is low enough to make further changes in moisture content almost imperceptible (Childs, 1969).…”

“…The rationale for this infiltration procedure came from observations of post-infiltration moisture distributions, as described by Biswas, Nielsen, and Biggar (1966), Childs (1969), and Gardner, Hillel, and Benyamini (1970 Childs (1969) for the case where surface moisture is maintained at a constant percentage, C, is shown in Figure 29. Because net precipitation was regarded as having zero dura tion in the soil moisture model, C was assumed to correspond to the soil saturation percentage provided ?CPX was greater than the air-filled pore space of the top layer.…”