Uptake of selected nutrients by temperate grasses and legumes

Temperate forages are used throughout the southeastern USA to provide feed for livestock when tropical and subtropical grasses are dormant and as a ha y source. Long-term utilization or broiler litter as a fertilizer in some a reas of the region has elevated soil levels of P and micronutrients. Our ob jective was to compare P, Cu, and Zn uptake among temperate forage species from a Savannah fine sandy loam soil (fine-loamy, siliceous, semiactive, th ermic Typic Fragiudult) amended with litter under a single-harvest system. Dry weight of ryegrass (Lolium multiflorum Lam,) herbage was greater than a ll other species except ball clover (Trifolium nigrescens Viv,) in 1997 and oat (A venn sativa L,) in 1998, Clovers were susceptible to Sclerotinia cr own and stem rot (Sclerotinia trifoliorum Erikss,) that reduced plant densi ty, vigor, and dry herbage weight. Although forage P concentration of all s pecies was similar to or greater than ryegrass, only crimson clover (T. inc arnatum L,) had P uptake equal to ryegrass during both years (mean of 23.4 kg ha(-1)). This was attributed to the high correlation between dry herbage weight and P uptake (r = 0.95 and 0.89 in 1997 and 1998, respectively), Le gumes typically had greater Cu and Zn concentrations than ryegrass, but onl y crimson clover and hairy vetch (Vicia villosa Roth) had comparatively gre ater Cu and Zn uptake during both years. The combination of desirable agron omic traits acid nutrient uptake capacity make annual ryegrass a superior t emperate forage species for use in southeastern pastures fertilized with br oiler litter.