Infiltration Capacity Curves for Sodium Affected Soils

摘要

Soil infiltration capacity (IC) must be considered for irrigation system design, soil conservation planning, and for evaluating basin runoff yields. The relationship of IC (inches/hour) as a function of electrolyte concentration (EC, meq/liter) of the saturation extract and the exchangeable sodium (Na) percentage (ESP) was examined, as well as ways to improve the mathematical equations used to analytically describe IC curves. A field infiltrometer was designed and constructed for field studies; a method incorporating the initial moisture in the profile (antecedent moisture) was developed. As an alternative to field study; IC curves were determined on undisturbed soil cores of varying salinity and 2-year irrigation treatment, planted to alfalfa. Study of the curves indicated that there is a continuous effect caused by increasing the Na adsorption ratio from 7.5-30. Watering with high EC water apparently reduces the Na dispersion.