|Wilkinson, S - USDA-ARS RETIRED|
|Bruce, R - USDA-ARS RETIRED|
Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 22, 1998
Publication Date: N/A
Technical Abstract: A four-year experiment was conducted to determine the rate of soil- carbon restoration on degraded cropland using Coastal bermudagrass that was grazed (mid-May to mid-October) at either high or low grazing pressure, harvested as hay or left unharvested. Crimson clover plus chemical fertilizer, poultry litter, or chemical fertilizer supplied nitrogen (N). Soil organic carbon (SOC) increased at a greater rate (0-2 cm depth) in grazed systems compared to hay or unharvested. Mean grazing days ha-1 year-1 were greater on the chemical fertilized paddocks compared to those receiving N from clover or poultry litter. Average grazing days ha-1 year-1 were approximately 897 and 1182 at the low and high grazing pressure, respectively. As animal grazing days ha-1 year-1 increased from about 600 to 900, average annual soil carbon accretion rate increased from approximately 120 to 200 g m2. High grazing pressure of bermudagrass in the summer can be used to increase animal productivity without detrimental effects on soil carbon accretion.