This work presents the effect exerted by bacterial inoculation in interaction with nitrogen-based fertilization on the total nitrogen content of the forage biomass, achieved from an association of Dactylis glomerata (40%) + Medicago sativa (60%). The researches were performed during 2006-2008, at USAMVB Timişoara, at the Research Centre for Pastures and Forage Plants, on a salty chernozem, moderately gleyed, with pH pH (H 2 O) of 6.21 on the depth of 0-13 cm. The experimental display was consisted of a bifactorial experience, with the following graduations: A – bacterial inoculation of the alfalfa within the association (a 1 – not bacterized, a 2 - bacterized); B – nitrogen-fertilization doses (b 1 - N 0, b 2 - N 30 , b 3 - N 60 , with application after each cutting). The results prove that bacterial inoculation of the alfalfa within the association, in the variants that were not fertilized with nitrogen, positively influences the total nitrogen content of the forage, by increasing it from 3.26% (unbacterized variant) to 3.43% (bacterized variant), in the frist year of vegetation, from 2.96% to 3.59%, in the second year of vegetation, and from 2.52% to 2.87%, in the third year. The mean of the vegetation years shows the importance of bacterial inoculation in alfalfa, planted in association with orchard grass, leading to the increase of the total nitrogen from 2.86 % in the unbacterized variant to 3.61%, in the bacterized variant. During the experimental period, the biggest total nitrogen amount was obtained in the second year of vegetation (240 kg/ha), and in the first and the third years of vegetation, the results were similar (207 kg/ha and 209 kg/ha). Every year of vegetation, the bacterized variants produced total nitrogen amounts that were much bigger than in the not-bacterized variants, 17.8%-fold bigger in the first year of vegetation, 28.1% in the second and 21.2%-fold bigger in the third year. The interaction of the factors studied proved that, on the average for the utilization period of the pasture consisted of Dactylis glomerata + Medicago sativa, the biggest total nitrogen content, 248 kg/ha, was achieved in the variant with bacterized alfalfa and N 60 -fertilization, namely 45%-fold bigger than in the variant that was not bacterized and nitrogen-fertilized.

bacterial inoculation; alfalfa; orchard grass; total nitrogen

Presentation: oral