Measuring Water Stored Temporarily Above the Field Moisture Capacity

Abstract

AbstractUsing a neutron type soil moisture meter, amounts of water temporarily stored in soil profiles above the field moisture capacity were observed for two silt loam and two clay loam soils. The amounts of temporarily stored water for the 5‐foot depth, ranged from 4.7 inches for one of the silt loams to 2.1 inches for one of the clay loams, immediately after 6 inches of irrigation water had penetrated into the soil. After 90 hours, temporarily stored water could still be detected ranging from 1.5 inches to 0.3 inches. The soils had previously been wetted to the field moisture capacity. Evaporation was prevented by a polyethylene cover. The field measurements, and some laboratory physical measurements which were made on core samples, indicated that one of the silt loams and two of the clay loams would probably have aeration problems due to the stored water. One of the silt loams had adequate aeration for all depths and times studied regardless of the addition of extra water. The laboratory physical measurements provided an explanation for the storage behavior found in the field. The relations between depth, soil moisture suction and soil moisture percentage were plotted as a three‐dimensional diagram which enables a clear general view of the behavior of the soil water.