Efeito de coberturas vegetais sobre a dinâmica da matéria orgânica do solo em sistema orgânico de produção de abacaxi

Abstract

The use of green manures as pre -cultivation of pineapple can be a viable alternative ecological practice to improve the physical, chemical and biological soil. This study aimed to evaluate the effect of different species of legumes and / or grasses used as green manure on the dynamics of soil organic matter in organic pineapple production system. The experiment was installed in Bioenergy - Organic Farm, on a Typic moderate dystrophic A, clayey, located in the Chapada Diamantina, municipality of Sheets, BA. We used the randomized complete block design with eight treatments and three replications. The treatments consisted of species: hemp (Crotalaria ochroleuca G.Don), jack bean (Canavalia ensiformis (L.) DC.), Pearl millet (Pennisetum glaucum R.Br), velvet bean (Mucuna pruriens (L.) DC), sorghum forage (sorghum bicolor (L.) Moench), and the combination velvet bean + sorghum (50 %) and also two control treatments with natural vegetation (VE) as a cover and another with the soil kept in clean (TEST). Crops cover crops were made in two cycles, each cycle lasted 80 days. Biomass production and leaf analysis of macro and micro nutrients of toppings, total C and N contents, physical and chemical characterization of soil humic substances, organic carbon under different degrees of oxidation and light organic matter were evaluated. It can be concluded that the green manures have different potential cycling C and nutrients. The millet shown high potential to maintain soil cover, the natural vegetation has an important cycling of C and nutrients and elimination of its total area ecological role represents a substantial loss of C and nutrients from the system. The use of grasses in the system can positively influence the penetration capability and water storage in the soil. The maintenance of cover crops in the system constitutes an important practice in the management and conservation of soil and can positively alter the physical and chemical properties of the soil when well managed.