The mineralizable N content reflects the amount of biologically
active N in the soil [48], i.e., the N that can be progressively
mineralized by microorganisms and thus made available to
growing crops. The mineralizable N content increased significantly
when fertilizer was applied, particularly PS45. This contrasts with
the higher residual soil NO3
eN content in the N300 plots, which
increases the risk of leaching. This combination of abundant
mineralizable N but scarce mineral N suggests the N cycle is more
tightly coupled to plant requirements in the PS45 plots, with
concomitant positive effects on soil fertility and the environment.
Similar results were reported in previous studies comparing
organic and mineral fertilizers for maize production