Vicia sativa and Vicia villosa enhance soil microbial composition, enzyme activities, and chemical properties in nutrient-deficient small-scale sugarcane plantation soils

Vicia sativa and Vicia villosa are nitrogen (N) fixing legumes commonly used as forage and cover crops due to their ability to enhance N fixation, soil N contributions, and enzyme activities in nutrient-deficient soils. Using V. sativa and V. villosa as cover crops can potentially improve nutrient cycling in nutrient-deficient sugarcane plantations owned by small-scale growers (SSGs) in KwaZulu-Natal, South Africa. This study investigated the chemical and biological inputs of V. sativa and V. villosa in nutrient-deficient sugarcane plantation soils. The nutrient concentration, N and phosphorus (P) cycling bacteria, and extracellular enzyme activities of soils collected from five small-scale sugarcane plantations were determined pre-planting and post- V. sativa and V. villosa harvest. Post- V. sativa and V. villosa soils had higher pH levels than pre-planting soils across all plantation soils. The number of plant growth-promoting rhizobacteria (PGPR) isolated from soils post- V. sativa and V. villosa harvest increased across all plantation soils. The Arthrobacter , Burkholderia and Paraburkholderia Pseudomonas were the most dominant genera isolated from post-harvest soils. The number of P-solubilising bacteria increased, increasing acid phosphatase activities. The findings of this study reveal that V. sativa and V. villosa increase PGPR, pH and enzyme activities in soils, making them sustainable options as cover crops for nutrient-deficient sugarcane plantation soils owned by SSGs.