Stocking rate effect on soil carbon and nitrogen in degraded soils

Stocking rate (SR) effects on soil organic carbon (OC) and nitrogen content resulting from 10 year continuous management were determined. Treatments were rotational grazing with four SR levels: light, moderate, heavy and non grazed. Two soils, a Durant loam (Udertic Argiustolls) and a Teller silt loam (Udic Argiustolls) located within common paddocks were sampled. Total OC mass in the surface 60 cm of the Durant soil averaged across treatments, was 95.7 t ha(-1) compared to 56.7 t ha(-1) in the Teller soil In the Durant soil, OC decreased as SR increased, with the non grazed exclosure having the greatest amount of soil OC In contrast, the Teller soil had similar amounts of OC in the soil profile with all grazing treatments, but less without grazing. Total soil nitrogen followed similar trends as the soil OC Soil properties should be considered to accurately assess the potential of grazing lands to sequester carbon.