Antecedent Rainfall and Tillage Effects upon Infiltration
1989
Freebairn, D. M. | Gupta, S. C. | Onstad, C. A. | Rawls, W. J.
Infiltration characteristics of a Port Byron (fine-silty, mixed, mesic, Typic Hapludoll) silt loam soil located in the karst terrain of southeastern Minnesota were determined using both ponded water and simulated rainfall. Three tillage treatments, with and without surface cover, were studied to provide a range of soil physical conditions. Simulated rainfall was applied after various amounts of both natural and artificial rain had fallen since tillage. Large differences in infiltration characteristics were attributed to the development of a surface crust. In the absence of a crust, this soil was highly permeable (>200 mm h⁻¹) while surface-crusted infiltration rates were as low as 10 mm h⁻¹. Infiltration characteristics were related to depth of rainfall since tillage, cover, and random roughness. Statistical analysis showed that >77% of variation in infiltration rate, Green and Ampt hydraulic conductivity, and curve number was explained by the depth of rainfall since tillage, surface cover, and random roughness. A procedure is suggested that describes the change in infiltration characteristics as a function of rainfall since tillage for various tillage conditions. Contribution from the Dep. of Soil Science and the Minnesota Agric. Exp. Stn., Univ. of Minnesota. Paper no. 16 253 Science Journal Series.
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