Organic carbon, bulk density, and microbial biomass in reseeded Kansas farmland soils.

Abstract

A study of organic carbon, soil bulk density, and microbial biomass in a native prairie and reseeded old fields was conducted from May 1988 through September 1989. All study cites were located on the Kenoma soil series in Lyon County, Kansas. Samples were taken from each site and analyzed for percent organic carbon using the procedure of Nelson and Sommers (1982). Microbial biomass was determined using the technique of Jenkinson and Powlson (1982). Soil bulk density was also determined following the procedure ondired by Burk et al. (1986). Results from the organic carbon determinations revealed that the most recently reseeded site had the lowest carbon levels (1.8%), followed by the oldest reseeding (2.19%) and the native prairie (4.26%), which had considerably higher carbon levels. The total microbial biomass found in the prairie (8.21 mg/100g) was more than that found in either reseeding (oldest 3.41 mg/100g and youngest 5.24 mg/100g). There was no statistical difference between the reseeding. Soil bulk density was least in the prairie (1.07 g/cm3), foiled by the oldest reseeding (1.17 g/cm3), with the youngest reseeding (1.29 g/cm3) showing the most compacted soil. The bulk density and organic carbon determinations suggest that the soils of the reseeding are moving toward a more native condition. However, microbial biomass did not show this trend.