Studiu cu privire la influenţa amestecului şi fertilizării asupra structurii covorului vegetal pe pajişti temporare înfiinţate pe bază de amestecuri complexe

Abstract

The researches have focused on the behaviour of some species of leguminous plants and perennial graminaceae and their influence plants on the forage yield in complex mixtures.At the some time the authors have analyzed the influence of the mixture and fertilization on the vegetal cover structure. From the mixtures under study, five were formed from six species, two perennial leguminous plants and four perennial graminaceae, and the other five mixtures were formed from seven species, from which two perennial leguminous plants and five perennial graminaceae. At the first five mixtures the perennial leguminous plants were represented by Medicago sativa and Lotus corniculatus, and the other five mixtures by Onobrychis viciifolia and Lotus corniculatus. The perennial graminaceae used in the first five mixtures were Dactylis glomerata, Festuca pratensis, Poa pratensis, Lolium perenne, and at the other five mixtures, the same species of graminaceae were used to which Bromus inermis was added. In the first year of vegetation the leguminous plant had the bigest percentage in the vegetal cover structure for all the mixtures studied. At the mixtures with Medicago sativa the leguminous plant has participated in the vegetal cover between 85 % at the mixture were Medicago sativa has participated with 60 % in the sowing norm and 73 % at the mixture with 20 % Medicago sativa. At the mixtures with Onobrychis viciifolia the leguminous plant has participated in the vegetal cover between 83 % at the mixture were Onobrychis viciifolia has participated with 60 % in the sowing norm and 69 % at the mixture with 20 % Onobrychis viciifolia. Within all mixtures, the changes in grass/legumes ratio have been determined by each category percentage in the mixture, by temporary meadow’s age species agresivity and less influenced by fertilization, either vinassa, manure or mineral.