Influence of green manure on the physical attributes of a dystrophic Yellow Latosol

Abstract

The objective of this study was to evaluate the performance of leguminous/grasses in rotation, used as green manure, in a dystrophic Yellow Latosol in the Cerrado biome in Maranhão/Brazil. A randomized block design was used in split plots, with plots consisting of the species Cajanus cajan, Canavalia ensiformis and Mucuna aterrima in the first year; and Pennisetum americanum, Sorghum bicolor and Sorghum sudanense in the second year, in addition to the control (spontaneous vegetation). The subplots were constituted by the evaluation seasons: season 1 (before planting) and season 2 (after the cover crops were grown). Productivity of green and dry phytomass, as well as the density and resistance to soil penetration at depths of 0-10, 10-20, 20-30 and 30-40 cm were tested. The species C. ensiformis and S. bicolor presented the highest productivity of phytomass, which demonstrates a better adaptation of these species to the soil and climate conditions of the region. The leguminous species of the first year did not provide improvements to the physical characteristics of the soil. On the other hand, the 2nd year grass species, when grown in rotation with legumes, contributed to the reduction of soil density and resistance to penetration.