Crop Rotation and Tillage Impact On Soil Nutrients.

The impact of tillage and crop rotation variations (2000 vs. 2009) on soil macro-and micronutrient contents was evaluated at the Ohio Agricultural Research and Development Center's northwestern branch at Hoytville, Ohio. A randomized complete block experiment in 2 tillage (no-till, NT vs. chisel plow, CT) x 5 crop rotations (corn, soybean, corn-soybean, soybean-wheat, and corn-soybean-wheat) in factorial arrangement was laid-out in the field in 2000. Composite soil core samples at 0-30 cm depth were randomly collected from GPS guided locations in 2000 and 20009, processed, and analyzed for pH, electrical conductivity, cation exchange capacity, bulk density, total C (C) and N (N), available P (P) and S, exchangeable K, Ca, Mg, Fe, Mn, Cu, Zn, B, and Mo. Results showed that pH, K, Fe, Mn, Cu, Zn, B, and Mo decreased and bulk density, C, and N increased in both CT and NT over time. However, the Fe content was significantly lower but the B content was higher in CT than NT. Soil pH and bulk density changed over time but was not significantly impacted by crop rotation. However, the C, N, P, K, Ca, and S impacted by crop rotation. The C and N contents were higher in soybean and corn-soybean-wheat rotation but P was higher in continuous soybean. In contrast, the S was higher in soybean-wheat rotation. While Fe and Zn contents were significantly decreased in corn-soybean, Mn content was lower in corn-soybean-wheat. Lowest B was measured in continuous corn. Mo was significantly decreased in continuous soybean followed by continuous corn and corn-soybean rotations. Nutrient indices, calculated based on macro- and micronutrient concentration, significantly impacted by tillage and crop rotation.