Nitrogen accumulation and efficiency in herbage depending on legume species in grassland sward

Abstract

The objectives of the experiment were to quantify the effect of different perennial legume species on N accumulation in harvested herbage, to assess the possible effect on nitrogen dynamics in grasses grown in mixture with legumes, to identify more suitable legume-based mixtures for efficient N use within perennial swards. Red clover (Trifolium pratense L.) and lucerne (Medicago sativa L.) were sown in monoculture or in mixtures with white clover (Trifolium repens L.) and perennial ryegrass (Lolium perenne L.) and timothy (Phleum pratense L.) for cutting. White clover was sown both in monoculture and with grasses. The grasses were also sown without legumes and either fertilized with 240 kg N ha-1 year-1 (N240) or not (N0). The N concentration, accumulation and use efficiency were estimated during three years of swards use. Nitrogen concentration in herbage and accumulation per unit of area varied in relation to legume species, year of sward use and cuts within year. All legumes had a positive effect on the improvement of N use efficiency. Keywords: nitrogen accumulation, nitrogen concentration, clover, lucerne, grasses, herbage