Characterization of Herbage, Litter and Soil As a Function of the Distance From Legume Trees in Silvopastoral Systems.

Pasture degradation has caused economic and environmental damage and compromised the sustainability of the livestock industry. One of the causes for this degradation is the low soil fertility, lack of fertilization, and poor-quality litter. This research evaluated herbage, litter, and soil characteristics in transect sampling across legume trees planted in double rows (10.0 m x 1.0 m x 0.5 m) on Signal grass (Brachiaria decumbens Stapf.) pastures in a silvopastoral system. Treatments were association of Signal grass pasture with the following tree legumes: “Sabiá” (Mimosa caesalpiniifolia I.) and “gliricidia” [Gliricidia sepium (Jacq.) Kunth ex Walp]. Treatments were replicated (4) in a complete randomized block design. Response variables were measured at five different points (0, 1.3, 2.7, 4.1 and 5.5 m away from the tree legume row). Measured responses included litter mass, herbage mass, LAI, litter N, herbage N, and light fraction of SOM. Triple interaction (distance x grazing cycle x species) occurred for litter N. The remaining variables showed interaction between distance x grazing cycle. Generally, there was an increase in the values of LAI with increasing distance from trees. Herbage N and litter N were higher near the legume trees. In silvopastoral system, there are influences from the tree component on most of the pasture characteristics. Litter deposition from legume trees are one of the major mechanisms for transferring nutrients to the herbaceous vegetation, affecting its biomass and chemical composition.