The objective of this study was to evaluate the use of biofertilisers for the production of alfalfa shoot, root and nodule dry matter, and also, to evaluate the chemical properties of the soil. This study was conducted in the greenhouse of the Support Department, Animal Production and Health, Faculty of Veterinary Medicine/UNESP, Araçatuba -SP, from May to October 2010. The experimental design was completely randomised with six biofertiliser doses (0, 25, 50, 100, 200 and 400 m 3 ha -1) and five replicates. The biofertiliser doses were the primary treatments and the cuts (five) were subplots. The cuts were performed, on average, every 27 days at 10 cm above the soil. At the end of the experiment, the roots, nodules and soil from all experimental units were collected for chemical analysis. We observed a linear increase in dry matter production of the shoots relative to the doses studied. The dry matter production of the roots and nodules was not significantly different. The chemical properties of the soil significantly improved for calcium and magnesium as well as the sum of bases and base saturation with biofertiliser application. Biofertilisers can be used for agricultural production and favourably alter the soil characteristics. Key words: Biofertiliser, Medicago sativa, nitrogen, nodules, roots ResumoO objetivo deste trabalho foi avaliar o uso de doses de biofertilizante na produção de matéria seca da parte aérea, raízes e nódulos da alfafa, e os atributos químicos do solo. O experimento foi realizado em casa de vegetação do Departamento de Apoio, Produção e Saúde Animal da Faculdade de Medicina Veterinária/UNESP, Campus de Araçatuba -SP, de maio a outubro de 2010. O delineamento experimental foi inteiramente ao acaso, sendo seis doses de biofertilizante (0, 25, 50, 100, 200 e 400 m 3 ha -1 ) e cinco repetições. As doses de biofertilizante foram consideradas como tratamentos principais e os cortes (cinco) como subparcelas. Os cortes foram realizados, em média, a cada 27 dias, a 10 cm de altura do solo. Ao final do experimento foram coletadas as raízes, nódulos e o solo de todas as unidades experimentais para análise química. Foi observado aumento linear na produção de matéria seca da parte aérea em relação as doses estudadas. A produção de matéria seca de raiz e nódulos não apresentaram diferença significativa. Para os atributos químicos do solo ocorreu resposta positiva para os teores de cálcio, magnésio, soma de bases e saturação de bases com a aplicação do biofertilizante. O biofertilizante pode ser utilizado como insumo na agropecuária para melhorar a produção e alterar favoravelmente os atributos do solo. Palavras-chave: Chorume bovino, Medicago sativa, nitrogênio, nódulos, raízes 1 Projeto financiado pela FAPESP. Processo nº 2010/09446-3.

The objective of this study was to evaluate the response of alfalfa (Medicago sativa L.) in the nutritional composition to the application of biofertilizers. The experiment was conducted with increasing doses of biofertilizers in a greenhouse at the Faculty of Veterinary Medicine / UNESP, Araçatuba -Sao Paulo, Brazil, from April to October 2010. The experimental design was completely randomized with six biofertilizer doses from cattle manure (0, 25, 50, 100, 200, and 400 m 3 ha -1 ) and five replications. Cuts were performed, on average, every 27 days, 10 cm above the ground when 10% of the plants were flowering. Biofertilization had a positive significant impact on foliar nitrogen, potassium, calcium, magnesium, sulfur, and shoot iron concentrations. The values of crude protein, acid detergent fiber, and neutral detergent fiber did not differ between doses of biofertilizers. Biofertilization is a viable alternative for nutrition of this species, showing positive results in the nutritional composition of alfalfa. However, but long-term studies are necessary to assess the environmental impact of these fertilizers.