Long-Term Tillage and Crop Rotations for 47-49 Years Influences Hydrological Properties of Two Soils in Ohio

Research is lacking concerning soil water retention (SWR) and infiltration rates (q(s)) as affected by long-term tillage and crop rotation. Thus, soil hydrological properties were measured at two long-term experimental sites near Wooster (49 yr) and Hoytville (47 yr) in central Ohio. The Wooster soil is silt loam in texture and well-drained, whereas, the Hoytville soil is clay loam in texture and poorly-drained. Tillage treatments were, no-tillage (NT), minimum-tillage (MT), and plow-tillage (PT), and crop rotations were continuous corn (Zea mays L), and corn-soybean (Glycine max L.) in a 2-yr rotation. Soil hydrological properties were compared with those of adjacent and undisturbed woodlots (WL). The SWR characteristics indicated higher volumetric water content at almost all matric potentials (Psi(m)) under WL soils than for the three tillage systems at both sites. Among tillage treatments, soils under NT had higher SWR than those under MT and PT for all four (0-10, 10-20, 20-30, and 30-40 cm) depths. In general, long-term NT contained a higher proportion of macropores (>1000 mu m) and micropores (<10 mu m), and hence had higher SWR than MT and PT for all depths. The q(s) was 1.9 and 4.2 times higher in well-drained soils under NT as compared to those under MT and PT, respectively, and 2.1 and 4.2 times higher in poorly-drained soils. Two physical based infiltration models, Green-Ampt and Parlange, fitted the measured infiltration data well with the coefficients of determination (r(2)) ranging from 0.91 to 0.98, and root mean square error values from 0.06 to 0.66 mm h(-1). Results support the conclusion that long-term (47-49 yr) use of NT practices in both well-drained and poorly-drained soils improves SWR, pore-size distribution, and q(s) compared to PT and MT practices.