Degradação de coberturas vegetais utilizando bolsas de decomposição

Abstract

He organic matter provides very important effects to the ground, as the increase of porosity, nutrient cycling, resistance to erosion, reduction in temperature, humidity increase among other factors essential for the maintenance of a soil. In this way, the objective of this work is to evaluate the degradation of the different cover crops and the humidity in the soil. The experiment was conducted in the experimental area of Agroecology of Universidade Federal do Recôncavo da Bahia, With the coordinates 24,4913419 East; 86,0000182 South (UTM). To evaluate the decomposition, two plant species were used: Brachiaria decumbens and Cajanus cajan (L.) with three repetitions for each. After collection, the plant material was dried in an oven at 55 °C, until constant weight and subsequently ground coffee in a mill for dried samples. The decomposition bags were used with dimensions of 21 cm x 29,7cm and a mesh aperture of 5 mm. In each bag was added 50 grams of dry matter of the aerial part of each cover and subsequently distributed in the experimental area in direct contact with the ground. The experimental design was in randomized blocks with 18 plots divided into 3 treatments: brachiaria (B. decumbens), andú (C. cajan) and moringa (Moringa oleifera)) with 3 repetitions each. The evaluations on the degradation plant and soil moisture content were performed at 15 and 30 days after the distribution of bags. The soil moisture was determined by the difference in weight at depths 0-10; 10-20; 20-30 and 30-40 cm. It was concluded that there was no difference between the decomposition of the dry biomass of the treatments C. cajan and B.decumbens in relation to time of decomposition of 0 to 15 days and 16 to 30 days, the treatment C. cajan achieved a lower rate of remaining dry biomass, the soil without vegetation coverage obtained in soil moisture content below to treatments with plant cover of C. cajan and B.decumbens and treatments with plant cover 16 to 30 days obtained higher moisture content in relation to the treatment of the period from 0 to 15 days.