Plants manipulate their rhizosphere community in a species and even a plant life stage-dependent manner. Here, we investigated the long-term impact of three type of soil management, two conventional and an organic regime, on soil biota (RNA and DNA) in fields naturally infested with the Columbian root-knot nematode Meloidogyne chitwoodi with pea (Pisum sativum) as the main crop.
Prolonged organic soil management was accompanied by significantly higher densities of bacterivorous nematodes, whereas levels of M. chitwoodi had dropped drastically. A closer look revealed that a local accumulation and activation of Pseudomonas, a genus that includes a number of nematode-suppressive species, paralleled the lower M. chitwoodi densities. This study underlines the relevance of taking along both resident and active fractions of multiple organismal groups while mapping the impact of e.g. crops and soil management regimes.