Soil carbon content, morphology and quality across three levels of pasture quality in the Chariton River Watershed, Iowa

Documenting changes in soil characteristics induced by agricultural practices is important in understanding how different management techniques affect the landscape. Three objectives of the research are: (1) to quantify soil organic carbon (SOC) content (2), to quantify soil morphological properties of the individual pedons, and (3) to determine soil quality relationship across three levels of pasture quality in the Chariton River Watershed, IA. Six pastures were studied in detail with two being each high quality, fair quality, and poor quality. Within each pasture, about ten pedons were collected in a summit-toeslope transect. Significant differences were found between pedons from the different pasture qualities with respect to SOC content, stable aggregate content, thickness of epipedon, and bulk density. SOC content of high quality pastures was 15 kg*m−2*m−1 which was approximately 2 and 4 kg*m−2*m−1 more than fair and poor quality pastures, respectively. Results also indicate that in most cases pedon properties and soil quality are proportional to the level of pasture quality. Overall, these data suggest that pasture quality is a good estimate of SOC content and soil quality