As seen in Fig. 1, the soil microbial biomass C ranged between 94 and 145 mg kg−1. The NK
treatment showed a lower biomass than the other treatments, probably due to its lowest available P
content. However, the variation among its four replicates was high (107.5 ± 14.2 mg kg−1). Statistically,
there was no significant difference in the microbial biomass C among the different fertilizing treatments