Alfalfa is a lot appreciated due to the multiple uses as fodder plant, having a great production capacity and a good perennity. Also is resistant at frost and drought, answering very well at watering. It has a great capacity of growth, and in exceptional culture conditions can be harvested of 5-6 times per year (Luminiţa Cojocariu, 2005). Alfalfa can be used as green fodder, hay, semihay, silo (in mixture with graminees) and at the preparation of combined forages. Also, alfalfa is a basic part of temporary meadows used by mowing (Dragomir N. and colab., 2005 ) . Alfalfa is forage with good quality and yield superior in the cold season because it can be transformed in hay. Alfalfa is a crop proper for organic fertilisation because it removes a great amount of nitrogen from soil and can diminish the high level of nitrites from the root area. Some researches realised in U.S. show that alfalfa yield can be improved applying manure in comparison with other fertilisation sources (Lory J.A., 2000; Herbert S.J. et Daliparthy J., 2001). The aim of this paper is to find the maximum production of this culture taking in consideration the fertilisation with chemical fertilisers in Batăr conditions, Bihor county. The research was carried out in the experimental fields that belong to the society SC Frevest SRL from Batăr locality, Bihor county, the experience being placed on a chernozem argiloiluvial soil. The experience is placed in accordance with the randomized blocks method, in three repetitions, a parcel surface is 45 m 2 . Sowing was made on October 05th 2010. In order to determine the production, the harvesting was done at 61th phenophase ( Beginning of flowering: 10% of flowers open) of alfalfa ( the extended BBCH-scale, general - U. Meier, 2001). After the analysis regarding the production capacity of alfalfa we can observe that exist differences statistically assured as beeing very significant, between alfalfa production obtained at N 50 P 50 K 50 fertilisation variant of 28,2 t.he -1 and N 50 P 50 K 50 + N 50 fertilisation variant that have obtained a production of 45 ,8 t.he -1 . The differences statistically assured as beeing very significant have been registered also between alfalfa production obtained at N 50 P 50 K 50 fertilisation variant of 28,2 t.he -1 and at N 50 P 50 K 50 + N 50 + N 50 fertilisation variant at which was obtained a production of 53,0 t.he -1 . Also, differences statistically assured as beeing significant have been registered between alfalfa production obtained at N 50 P 50 K 50 + N 50 fertilisation variant of 45,8 t.he -1 and N 50 P 50 K 50 + N 100 fertilisation variant at which have been obtained a production of 53,0 t.he -1 .

alfalfa, production, fertilisation, optimisation.

Presentation: oral