Relation of Organic Carbon to Soil Properties and Climate in the Southern Great Plains

The proportion of Mollisols in the Southern Great Plains ranges from 1% to > 90% of counties with completed soil surveys. A study was made on data from 65 pedons spaced as equally as possible across the area. All of the soils studied had grassland vegetation, were on uplands, were not excessively wet, and did not have high shrink‐swell potential. Stepwise multiple regression analyses were made on percent organic carbon vs. percent clay, percent silt, base saturation, mean annual precipitation, and mean annual temperature. Results indicate a significant relationship between organic carbon and clay with a lesser relationship with precipitation. The other variables did not improve the predictive equation.