Management of marandu grass pasture increases soil carbon and nitrogen stocks in forest grazing systems in the brazilian cerrado

Abstract

This paper aimed to evaluate the influence of management practices of marandu grass, at eucalyptus shading levels in a forest grazing system, on organic carbon (OC) and nitrogen (N) stocks, and on soil chemical characteristics in the Brazilian Cerrado. The experimental design adopted was entirely random with five repetitions. In the plots were allocated the environments with different light availability, and a treatment with marandu grass in full sun. The management of marandu grass pasture was distributed in the subplots with pre-pasture at 30, 40, 50, and 60 cm high. Evaluations were repeated in two crop cycles in year 1 and year 2. Soil chemical characteristics, OC and N stocks were analyzed. The management of marandu grass at 50 cm height in the forest grazing system provided higher levels of OC, N, organic matter in the soil and an increase in fertility, compared to monoculture pasture, with repercussions in two years. The integration of eucalyptus and marandu grass pasture contributes with greater stocks of OC and N in the soil strips closest to the tree row, due to greater nutrient cycling. Marandu grass in forest grazing systems with shading varying from 40 to 60% present greater efficiency and maintenance of soil chemical attributes, demonstrating greater sustainability compared to monoculture pastures.