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EFFECT OF LANDSCAPE POSITION AND ASPECT ON AVAILABLE SOIL WATER AND WATER RECHARGE IN SOUTHEAST NEBRASKA
Abstract
In dryland farming, stored soil water is an essential source of water for crop production. Since slope aspect and position influence the microclimate of the soil and determine soil response to runoff, erosion, and deposition, they control to a great extent the amount of water stored in the soil for plant use on sloping topography. The effect of slope aspect and position on soil water and its changes throughout the year in dryland farming were studied in the field near Lincoln, Nebraska. North, south, and east-facing slopes of Wymore silty clay loam were selected for study. Four positions on each slope including summit, shoulder, backslope, and footslope were identified. Water content of the soil from 0 to 150 cm depth in 30 cm increments was measured weekly by neutron scattering for two years. Daily precipitation was recorded. Results indicate that slope aspect and position significantly influenced the amount of available water in the pedon. Twenty percent more water was available in soils on north-facing slope than in soils on south-facing slope at planting and throughout the year. Soils on the east-facing slope were the driest. Within slope positions, soils on the backslope and footslope contained an average of 4 cm more available water than soils on the summit and shoulder. Available water throughout the pedon was influenced by slope position. However, the greatest effect of slope position was in the 60-120 cm depth. Soils on the north-facing slope were 10 percent less efficient in water storage than soils on south and east-facing slopes during all recharge periods. Soils on the footslope were 6 to 8 percent more efficient than other positions during the year. Water storage efficiency of the soil at all slope positions and aspects appeared to be higher in fall than spring. High correlation coefficients (r) existed between available soil water and rainfall during each fall and spring season, separately. Monthly rainfall appeared to be an effective variable for prediction of available soil water in both fall and spring seasons in all slope positions.
Subject Area
Agronomy
Recommended Citation
HANNA, ABDULAZIZ YALDA, "EFFECT OF LANDSCAPE POSITION AND ASPECT ON AVAILABLE SOIL WATER AND WATER RECHARGE IN SOUTHEAST NEBRASKA" (1982). ETD collection for University of Nebraska-Lincoln. AAI8227014.
https://digitalcommons.unl.edu/dissertations/AAI8227014