Submitted to: International Soil Tillage Research Organization Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/29/2000
Publication Date: N/A
Technical Abstract: For many SE USA soils, deep tillage is necessary to disrupt compacted zones for optimal crop production using conservation tillage. Our objective was to evaluate vertical and horizontal stratification of plant nutrients in the soil as affected by surface and deep tillage using controlled traffic. Soil samples were collected from both in the row and in the row middles after three years of growing wheat (Triticum aestivum L.) doublecropped with soybean (Glycine max L. Merr.) and then again after three years of continuous corn (Zea mays L.). The soil type was Goldsboro loamy sand (fine-loamy, siliceous, thermic, Aquic Kandiudult). Nutrient analysis for P, K, Ca, and Mg was conducted on soil from four depths. Higher concentrations of P, Ca, and Mg occurred near the soil surface with the conservation tillage treatment than with the disked treatment. Surface tillage did not affect K distribution. After six years, soil that was subsoiled was lower in K concentration at the top of the B horizon and higher in K concentration at the surface than soil that was not subsoiled. Also after six years, soil P concentrations were lower in the row than in the mid-row while soil K concentrations were higher in the row than in the mid-row. These data will be useful in developing improved soil sampling schemes for conservation tillage production systems using controlled traffic in the SE USA.