RESEARCH ON THE PRODUCTION POTENTIAL OF ALFALFA MIXED WITH ORCHARD GRASS UNDER INFLUENCE OF MINERAL FERTILISATION

I.C. Muntianu, V. Vîntu, C. Samuil, M. Stavarache

Abstract
In Romania, the need for performance and the intensification of the sown grasslands is increasing and more and more farmers use the imported seeds of valuable herbaceous species. This study was conducted during three production cycles, and the main objective was to determine the production of dry matter (DM) and crude protein (CP) made under the influence of mixture and fertilization with nitrogen on P50 agrofund to one of the known Romanian cultivar of alfalfa and a more productive European cultivar of orchard grass. Another objective was the evolution of canopy cover structure. To achieve these objectives, three variants of mixture were tested between alfalfa and orchard grass that were applied to four rates of mineral fertilizers. The mixture 75% alfalfa (Medicago sativa L.) and 25% orchard grass (Dactylis glomerata L.) under the effect of dosing with N₁₀₀P₅₀ and N₇₅P₅₀ achieved the highest production increase of DM on cycle I, 116% (4.68 Mg ha^-1 DM) and 113% (4.54 Mg ha^-1 DM) compared to the control, unfertilized alfalfa in pure culture (4.02 Mg ha^-1 DM). The highest increase for the CP yield was obtained on cycle I from the 100% alfalfa fertilized with doses of N₁₀₀P₅₀, 143% (955 kg ha^-1 CP) from 100% alfalfa unfertilized (666 kg ha^-1 CP). At all cycles, in terms of canopy cover structure, alfalfa had a higher share in mixtures compared to orchard grass. Exception only on cycle III, where on mixture 50% alfalfa + 50% orchard grass, orchard grass at higher doses of nitrogen had a higher share to alfalfa (56% orchard grass / 44% alfalfa at N₁₀₀P₅₀ dose and 54% orchard grass / 46% alfalfa at N₇₅P₅₀ dose).

Key words: mixture, fertilization, alfalfa, orchard grass, production