MASS YIELD OF GREEN MANURE AND IMPACT ON SOIL FERTILITY IN SUCCESSION OF ORGANIC CROPS

The aim of this study was to evaluate mass production, nutrient contents and input of green manures used in the altitude region of Espirito Santo to the implementation of appropriate practice no tillage vegetables under organic management. This study also aimed evaluate the evolution of soil fertility as a consequence of two pre-crop maize and crotalaria (February 2009 and October 2009) and two pre-crop oat and white lupine (July 2010 and May 2011). The experiments were carried in the INCAPER's Agroecology Reference Area at Domingos Martins-ES. Treatments consisted of a control (no straw) and three straw production systems: 1) cropping of grasses (oats or corn), 2) cropping legume (crotalaria or white lupine) and 3) intercropping of grasses/legumes (corn/crotalaria or oat/lupine). In February 2009, the production of green mass system corn and corn/crotalaria reached 73.6 and 64.5 t ha(-1), respectively. In July 2010, the production of green mass systems lupine and oat/Lupin reached 76.3 and 88.3 t ha(-1), respectively. The green manures intercropping proved to be excellent management option for organic systems, because added 811.4; 941.2; 263.5; 78.6; 51.9 kg ha(-1) of N, K, Ca, Mg and S, respectively, values those at or above the single pre-cultivation. The effects of pre-cultivation of green manure on soil chemical properties in organic management, except for the contribution of nitrogen, were similar to control in all seasons, because of the base fertilization with organic compost in all treatments, maintaining high fertility rates in the area.