Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2003
Publication Date: November 2, 2003
Citation: Smith, D.R., Stott, D.E., Warnemuende, E.A., Norton, L.D. Nutrient profiles in soils from long-term tillage plots. CD-ROM. Denver, CO: American Society of Agronomy Annual Meetings. 2003. Technical Abstract: The effects of tillage and crop rotation on grain yield and nutrient uptake have been well documented. However, little research has been conducted that documents the impacts of these management practices on nutrient concentrations in the soil by depth. This study was conducted on two soils where long-term studies had been conducted. The treatments in both studies were use of no-till or conventional tillage practices, and continuous corn, continuous soybean or corn/soybean rotation. Soils samples were taken to a 1 m depth and analyzed for plant available nutrients and soil C. Results indicate that in the surface layers, no-till contained the greatest amount of C, which rapidly decreased with depth. In the conventional tillage treatments, soil C was higher at the 5-10 cm depth than the 0-5 cm depth, but decreased with increasing depth below that. Available P concentrations were the highest in the upper 20 cm under continuous corn management, while there was relatively little change in P concentration down to 30 cm for plots in continuous soybeans. It appears as though the corn/soybean rotations were able to utilize the nutrients in the soils more readily than the other two rotations, indicating that when this type of management is used, fertilizer requirements for micronutrients should be addressed. The impact of this research will be to aid extension personnel in their recommendations for macro- and micronutrient recommendations based on tillage and crop rotation, in addition to yield goals.