Evaluation of Buffel Grass Forage Production, Soil Microbial Biomass, and Enzymatic Activity in Silvopastoral Systems

The adoption of silvopastoral systems enables the achievement of sustainable intensification using multiple arrangements and species in the same area. This study aimed to evaluate the forage production of buffel grass and determine soil microbial biomass and enzymatic activity in two arrangements of a silvopastoral system. The study design was a randomized block with four replicates using a 2 x 4 factorial arrangement. The factors were two arrangements of the silvopastoral systems (buffel + Eucalyptus urograndis = SPS1 and buffel + pigeon pea + E. urograndis = SPS2) and four distances from the E. urograndis trees (2, 4, 6, and 8 m). Soil sampling was carried out at 0–5, 5–10, and 10–20 cm depths to evaluate microbial nitrogen (Nmic) and carbon (Cmic), while the activity of β-glucosidase and urease enzymes was evaluated at 0–5 and 5–10 cm. Buffel grass in the SPS1 showed higher canopy height, total dry mass, and root mass values. In SPS1, the highest total dry mass (3290.7 kg·ha−1) was observed at 8 m from the trees. At a 5–10 cm depth, Cmic was higher at 2 m than 8 m from the trees. The highest value of Nmic was found at 5–10 cm, at a distance of 2 m. The SPS2 showed a higher Nmic than the SPS1 at the 10–20 cm depth. The β-glucosidase activity was higher at a distance of 2 m in SPS1 at 0–5 and 5–10 depths. Urease activity was lower at 8 m at both depths. Thus, we observed the highest values of root-and-shoot biomass of buffel grass in SPS1 system at 8 m from the E. urograndis trees. However, the soil microbial response indicated that the intensification using tree, legume and grass in silvopastoral systems increased soil microbial activity.