Biofertilizer made from rocks with Acidithiobacillus releases nutrients for plants and reduces the environ-mental impact of fertilizer on the soil. The aim of this study is to evaluate the effects of PK rock biofertilizersmixed with earthworm compound and inoculated with free living diazotrophic bacteria and arbuscularmycorrhizal fungi (AMF) on the nodulation, yield and nutrient uptake of cowpeas (Vigna unguiculata) andon the soil attributes in field conditions. In a greenhouse experiment, three rates (4.0 t ha−1, 6.0 t ha−1,and 8.0 t ha−1) of biofertilizer were compared with the addition of AMF (Glomus etunicatum and Gigasporaalbida). A treatment with earthworm compound (20 t ha−1) without AMF was used as a control. In thefield experiment, the treatments were as follows: three rates of biofertilizer (4.0, 6.0 and 8.0 t ha−1); min-eral fertilizer at the recommended rate (RR) and two times RR; and earthworm compound (20 t ha−1). G.etunicatum was applied to all treatments. In both experiments, the seeds were ino