Tillage and Crop Influences on Physical Properties for an Epiaqualf

Tillage impacts on soil properties differ among soils. This study investigated tillage, cropping, and wheel traffic (WT) effects of 13‐yr of no‐tillage (NT), chisel plow (CP), and moldboard plow (MP) under continuous corn ( Zea mays L.) and soybean ( Glycine max L.) including a check treatment of continuous cultivated fallow (CCF) on bulk density (ρ b ), organic matter (OM), soil–water retention, and saturated hydraulic conductivity ( K sat ) on a Mexico silt loam (fine, smectitic, mesic, Aeric Vertic Epiaqualf). Possible relationships between runoff and effective K sat ( K eff ) were also studied. Soil properties were determined on intact cores of 76‐mm diam. collected from trafficked and nontrafficked positions for the 0‐ to 100‐mm and 100‐ to 200‐mm depths from the Midwest Research Claypan Farm erosion plots near Kingdom City, MO. Results show that the CCF had lower ρ b , OM, K sat , and higher surface runoff than other treatments ( P < 0.01). Tillage effects on soil properties among NT, CP, and MP were small and crop dependent. Corn had lower K sat (7.3 mm h −1 ) than soybean (11.7 mm h −1 ; P < 0.01). Conversely, corn had slightly higher ρ b (1.53 Mg m −3 ) than soybean (1.48 Mg m −3 ; P < 0.01). The ρ b increased from 1.47 to 1.52 Mg m −3 and OM decreased from 15.5 to 14.0 g kg −1 with depth ( P < 0.01). Wheel traffic reduced K sat by three times and increased ρ b by 6% ( P < 0.01). Bulk density was a significant predictor of log K sat ( P < 0.01) but not for soils under CCF management. The K eff was not related to runoff with the exception of the CCF treatment, which had slightly more runoff and lower K eff ( P < 0.05). Overall, tillage treatments had no significant effects on soil properties; however, cropping and WT had small significant effects on ρ b and K sat