Atributos fitotécnicos de plantas de cobertura para a proteção do solo

Abstract

Cover crops consist in an effective alternative for soil protection, however, in the south of Minas Gerais there are few studies about species indicated to be used in this technique. Thus, this work aimed to evaluate the cover-management index, and green mass and dry mass productivity for sunn hemp (Crotalaria juncea L.), jackbean (Canavalia ensiformis DC.), and milhet (Pennisetum glaucum (L.) R. Br. var. ADR 7010 crops, with line space of 0.25 and 0.50 m. Experiment was performed in the Lavras County, Minas Gerais state – Brazil, between November 2007 and April 2008, corresponding the crop cycle. Cover-management index was evaluated with a horizontal apparatus. Wood box of 1 m2 was employed in order to quantize the green mass. Dry mass was determinate after dehydration of 500 g of green mass in the oven at 65 °C, until constant weight. The jackbean proportioned the best soil protection, being the cover-management index equal 95.40%. The sunn hemp showed the best green mass (62.50 t ha-1 ) and dry mass (23.25 t ha-1 ) productivity. The crop line space did not have an effect on soil cover, green mass productivity of sunn hemp, and dry mass productivity of jackbean and milhet.