Tillage and fallow effects on selected soil quality characteristics of former conservation reserve program sites

Tillage and fallow have been suggested as management options for converting Conservation Reserve Program (CRP) areas to cropland This study was conduc ted to measure selected soil quality characteristics of former CRP sites in Mississippi, Nebraska, and South Dakota that were tilled and then left fal low for 21 or 22 months. Soil samples from depth intervals of 0-7.6 cm and 0-30.5 cm were collected for laboratory assessment of the following soil qu ality indicators: bulk density, EC, pH, total C, organic C, total N NO3-N, NH4-N, PO4-P, biomass C, biomass N, anaerobic NH4-N, lab respiration 0-10 d ays and lab respiration 10-20 days. When compared to undisturbed CRP, incre ased NO3-N values on the tillage and fallow plots suggest that under the ex treme renditions employed in this study, organic residues were being minera lized. Re a result, significant reductions in organic C and total N were fo und at the 0-7.6 cm depth on each of the fallow plots. Thus, to reduce soil quality degradation, use of minimum-till or no-till management systems may be best suited for CRP areas which are converted to cropland.