Physiological Analysis of Growth and Nitrogen Metabolism of Intercropped Pasture Species Subterranean Clover (Trifolium Subterraneum L.) and Cocksfoot (Dactylis Glomerata L.) Supplemented with Different Inorganic Nitrogen

Growth and physiological parameters of intercropped subterranean clover (Trifolium subterraneum L.) and cocksfoot (Dactylis glomerata L.) were investigated under controlled and field conditions. Nitrogen nutrition was accomplished in symbiotic and heterotrophic form in both studied species under controlled concentration of mineral elements in the media and by inoculation with appropriate rhizobial strain. Intercropped variants were also grown in sand culture as follows: subterranean clover - 100%, cocksfoot - 100%, subterranean clover:cocksfoot - 75:25(%), subterranean clover:cocksfoot 50:50(%) and subterranean clover:cocksfoot - 25:75(%). In hydroponic cultures subterranean clover to cocksfoot proportion was always 50:50(%). Subterranean clover reacted positively with growth up to 1.25 mM nitrate concentration in the medium with stimulation of number of nodules formed and their nitrogenase activity. When separately grown both subclover and cocksfoot reacted with higher plant biomass formation under higher nitrate nutrition. When intercropped the process of growth stimulation in subclover was more prominent than in cocksfoot.