THE IMPORTANCE OF EROSION IN THE CARBON BALANCE OF PRAIRIE SOILS

Abstract

Twenty-six cultivated benchmark sites established in the mid-1960s were resampled in the early 1980s. Most of the sites were coarse textured and field observations indicated that these were subject to wind erosion. The original samples and the samples collected in the 1980s were analyzed for 137Cs and organic C. From these data soil erosion or deposition and organic C losses from the 0 to 0.15-m layer were calculated. Soil losses up to 10 kg m−2 yr−1 were calculated, but some sites showed deposition. Changes in organic C in the 0 to 0.15-m layer could be explained largely by erosion and deposition, indicating that at these sites (mainly on upper or middle slopes that had been cultivated since before the mid-1940s) erosion was the major factor responsible for the observed organic C loss. Key words: Organic carbon loss, erosion, mineralization