PLANTAS DE COBERTURA DE SOLO E SEUS EFEITOS NO DESENVOLVIMENTO DA CULTURA DO ARROZ DE TERRAS ALTAS EM CULTIVO ORG NICO

COVER CROPS EFFECTS ON THE DEVELOPMENTOF UPLAND RICE UNDER ORGANICFARMING SYSTEMThis research was conducted in an experimental area inSanto Ant nio de Goiás (16o28'S, 49o17'W and altitude 823 m),Brazil, during the months of June, 2004, and March, 2005. Theupland rice variety Aimoré was used along with several covercrops aiming to evaluate leaf area, number of tillers, dry matter,and nitrogen content in the phytomass during the rice crop cycle.The experimental design was the randomized blocks one, withfive treatments and four replications. The treatments consistedof different cover crops, such as velvet bean (Mucuna aterrima),sunn hemp (Crotalaria juncea), dwarf pigeon pea (Cajanus cajan),broom sorghum (Sorghun bicolor), and a check treatment withspontaneous vegetation growing among the rice plants. Theleguminous plants, specially C. juncea, presented better resultsin tillering production, leaf area index, dry matter yield, andaccumulated nitrogen content, if compared to the treatments wheregrasses were used as soil cover crop. It was concluded that ricepresented a satisfactory development in the different soil covertreatments, specially after leguminous cultivation.