Impact of Crop Production on the Physical Status of a Typic Albaqualf
1989
Scott, H. D. | Wood, L. S.
Extensive tillage during long periods of time affects soil productivity by altering soil properties. Quantitative measurements were made to determine the combined effects of duration of tillage and production of soybean [Glycine max. (L.)] and rice (Oryza sativa) on selected physical and chemical properties of a Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualf). Four adjacent fields were sampled which included a virgin prairie and three fields in cultivation for 1, 12, and 30 yr. Undisturbed soil cores were taken at 0.05-m depth intervals to 0.15 m and analyzed for soil water retention at 10, 30, 50, 80, 100, 500, and 1500 kPa, bulk density and saturated hydraulic conductivity. Organic matter content, pH, and particle size were determined on disturbed samples. Compared with the cultivated soils, the prairie had higher organic matter contents. The 12-yr and 30-yr fields in cultivation had higher pH values and bulk densities but lower water retained at a given pressure than the prairie and 1-yr field in cultivation. No differences were found with respect to particle-size distribution. For a given soil property, values of CV were affected by time in production but not by depth. The CV was low in the prairie, increased in the 1- and 12-yr fields and in the 30-yr field was similar to values found in the prairie. The greatest changes in organic matter and bulk density occurred in the initial 12 yr of cultivation. The temporal variability of organic matter contents in the surface 0 to 0.05-m interval was mathematically modeled with both constant and variable rate equations. Published with the approval of the Director of the Ark. Agric. Exp. Stn.
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