Turkish Journal of Agriculture and Forestry




Soil carbon (C) dynamics is an important aspect of the global C cycle. Soils can be a sink or source for atmospheric CO_2 depending upon management. Tallgrass prairie and wheat (Triticum aestivum L.) are 2 dominant ecosystems in the Great Plains. This study determined the distribution of C in these 2 ecosystems. Soil C pools, plant root biomass, and aboveground plant biomass were determined at a wheat (winter wheat) and a tallgrass prairie site in northern Oklahoma from 1998 through 2001. The objectives of this study were to determine C storage and changes in soil organic matter in tallgrass prairie and wheat ecosystems under similar environmental conditions and soil characteristics. Soil C was assessed by measuring soil C pools (active, slow and recalcitrant). Mineralizable C and N (C_o and N_o) were determined by long-term laboratory incubation, 314 days at 35 °C. Soil C and N content was 2 times greater in the prairie than under wheat. The greater level of C_o and N_o occurred in prairie. Wheat had proportionally greater mineralizable C and N than did prairie, but microbial biomass was the opposite, being greater in prairie. Wheat had more dynamic C pools with a faster turnover rate than did prairie. The more dynamic C pools with a faster turnover rate in wheat was the result of the greater disturbance effects of intensive tillage practices on soil structure.


Soil carbon, carbon pools, mineralizable carbon, microbial biomass carbon, recalcitrant carbon

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