Biological Condition of an Agricultural Soil Six Years after Conservation Reserve

• Published in: Transactions of the Kansas Academy of Science 1995-12, Vol.98 (3/4), p.102-112
• Main Authors: Noll, Michael G., Sorenson, Curtis J., Rice, Charles W.
• Format: Article
• Language: English
• Subjects: Agrology; Forest soils; Microbial biomass; Organic farming; Prairie soils; Prairies; Silt loam soils; Soil microorganisms; Soil quality; Tillage
• ISSN: 0022-8443; 1938-5420
• DOI: 10.2307/3628234

Microbial properties of Kenoma silt loam soil in Coffey County, Kansas, were investigated for a native tallgrass prairie, a field currently under cultivation, and a previously cultivated field that was reseeded to native grasses in 1986 as part of the Conservation Reserve Program (CRP). Soil samples were taken from the surface 10 cm and analyzed for soil respiration, microbial biomass carbon (C) and nitrogen (N), N availability, and dehydrogenase activity. In comparison to soils in native prairie, measures of microbial quality in soils under cultivation decreased as follows: microbial biomass C and N by 67%, nitrogen availability by 37%, dehydrogenase activity by 68%, and respiratory rate by 69%. When CRP land was compared with soils in cultivation, no significant differences could be detected in terms of microbial biomass N, N availability, and dehydrogenase activity. The CRP land showed lower values of microbial biomass C, but a significantly higher respiratory rate. These results led to three important conclusions: First, the results strongly confirm that cultivation has a profound impact on native prairie soils. Second, the levels of soil microbial quality parameters in the reseeded prairie were not similar to those in the native prairie after a period of 6 years. Third, a higher respiratory rate in the reseeded prairie indicates a response of the soil microbial community to the reestablishment of permanent prairie vegetation. The latter point also was supported by a greater proportion of active pools of C and N in the reseeded prairie.