The diversification of tropical pastures with legumes (trees) for increased forage and animal productivity has been advocated. Nevertheless, effects on soil quality and belowground biodiversity, and the implications for sustainable intensification remain poorly documented, particularly when cattle grazing is included in the study. We evaluated the impact of forage system diversification with herbaceous and woody legumes on soil properties and soil macrofauna communities and their spatial heterogeneity in a three-year-old field trial in Cauca Valley, Colombia.
This study assessed the carbon (C) budget and the C stocks in major compartments of the soil food web (bacteria, fungi, protists, nematodes, meso- and macrofauna) in an arable field with/without litter addition. The C stocks in the food web were more than three times higher in topsoil (0–10 cm) compared to subsoil (>40 cm). Microorganisms contained over 95% of food web C, with similar contributions of bacteria and fungi in topsoil. Litter addition did not alter C pools of soil biota after one growing season, except for the increase of fungi and fungal feeding nematodes in the topsoil.
