Submitted to: Mississippi Water Resources Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 19, 2000
Publication Date: N/A
Interpretive Summary: Repeated application of animal manure to hay fields and pastures results in the accumulation of nutrients in the soil that if allowed to leave the field in rain water runoff, may pollute streams, rivers, and lakes. The level of nutrients in the soil can be reduced by harvesting hay and removing it from the field. We conducted studies to determine which hay crops removed the most nutrients from the soil. Seven different varieties of bermudagrass, the most prevalent perennial forage in the Southeast, and seventeen annual forages were fertilized with either swine or chicken manure. Nutrient uptake by common bermudagrass, a type native to most hay fields and pastures, was equivalent to hybrid bermudagrasses when it was fertilized with liquid swine manure, but was less than the hybrids when it was fertilized with dry chicken manure. Ryegrass, the most inexpensive e and commonly used annual forage had greater nutrient uptake than other annual forages. Swine and poultry producers who manage hay fields to maximize yield will remove the greatest quantity of nutrients from their soil.
Although soil nutrient levels may be reduced very slowly due to continued manure application, intensive forage crop production represents an important component of nutrient management. Enhanced nutrient uptake is contingent upon selection of appropriate forage species and cultivars. Among perennial forage crops typically grown in the southeastern USA, bermudagrass(Cynodon dactylon (L.) Pers.) has the greatest capacity to remove nutrients because of its yield potential. Nutrient uptake can also be improved by utilizing temperate annual forages during the winter and spring. At two Mississippi locations, nutrient uptake of these forages fertilized with either swine effluent or broiler litter was evaluated. Annual N and P uptake by common bermudagrass was similar to or greater than the hybrids Alicia, Brazos, Coastal, Russell, Tifton 44, and Tifton 85 when fertilized with swine effluent. When fertilized with broiler litter and without the benefit of irrigation, nutrient uptake by the hybrid bermudagrasses was generally greater than common. Among seventeen temperate annual grasses and legumes grown at the same sites, annual ryegrass (Liolium multiflorum Lam.) yielded greater dry weight than all other species except ball clover (Trifolium nigrescens Viv.) and oats (Avena sativa L.). In the single-cut system employed, clovers were susceptible to Sclerotinia crown and stem rot that reduced plant density, vigor, and yield. Among temperate annual species, there was a high correlation between dry weight and P uptake r = 0.95 and 0.89 in 1997 and 1998, respectively).