Submitted to: Journal of Sustainable Agriculture
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/25/2005
Publication Date: 6/28/2006
Citation: Sistani, K.R., Mclaughlin, M.R. 2006. Soil nutrient dynamics from swine effluent application to common bermudagrass overseeded with cool-season annuals. Journal of Sustainable Agriculture. 28:101-116. Interpretive Summary: The practice of using cool-season annual species overseeded in bermudagrass, a warm-season perennial has many advantages including removing nutrients from soil during bermudagrass dormancy in winter months, and also providing nearly year-round forage production for grazing or haying. It may also be used as justification for the extended application of effluent beyond the time limit mandated by Natural Resource Conservation Service (NRCS) Code 359. Generally annual and perennial forage crops serve as an important component of nutrient management plans for farms where animal manure is routinely applied. An experiment was conducted to investigate the nutrient status of the soil under the year-round pasture production system consisting of three cool-season annuals overseeded in common bermudagrass. Growth of common bermudagrass was not adversely affected by overseeding with any of the cool-season annual forages tested. Most of the soil nutrient element concentrations increased during the 3-yr study, particularly in the top 5 cm surface soil. Overseeding common bermudagrass with berseem clover or annual ryegrass can be an advantageous practice compared to growing bermudagrass alone. The quantity of the effluent application must be properly coordinated with the nutrient requirements of the growing forages in order to minimize the build up of any nutrient in the soil.
Technical Abstract: A 3-year study was conducted to investigate the major nutrient dynamics in soil receiving swine effluent as the sole source of plant nutrients for warm-season perennial bermudagrass and cool-season annuals. Berseem and crimson clovers, ryegrass, and wheat were seeded in common bermudagrass for a year-round nutrient uptake and spring through summer haying. Bermudagrass dry matter of 9.0 Mg ha-1 (3-yr average) was not impacted by the overseeding treatments. Most of the soil nutrient element concentrations increased during the study, particularly phosphorus in top 5 cm of the soil surface. The increase of Fe and NO3-N concentration at the 0-5 cm depth was high. Double cropping can be a better practice than growing bermudagrass alone, but, the effluent nutrient application must be coordinated with the nutrient requirements of the growing forages in order to minimize the build up of any nutrient in the soil.