Orchard floor management effect on soil free-living nematode communities

Context. Although both plant cover and mulch are considered for erosion control in arid and semi- arid regions, they have divergent impacts on soil ecology. We examined the effects of orchard floor management practices on the density and diversity of soil free-living nematode communities and relevant soil abiotic properties. Methods. Soils were sampled in winter in a citrus orchard in the Sharon region of Israel from plots that for 6 years had been under (1) annual native species; or (2) Avena saliva and Vicia villosa, planted between tree rows; or (3) woodchip mulching along tree rows. There were two control sites: (4) bare soil between tree rows and (5) bare soil along the tree rows (both common practice). Key results. Nematode communities and their trophic diversity were significantly impacted by floor management. Significant increases in soil moisture under plant cover, and higher organic matter and water-holding capacity for all covered orchard floors could be related to nematode changes. Shifts in nematode feeding group structure suggest a shift in the type and availability of soil carbon pools. Conclusions. There was a strong association between orchard floor management and soil free-living nematode communities, indicating a shift in the soil food-web structure and functionality. Bare soil harboured fewer nematodes, but more complex communities dominated by persisters, while seeded plant cover had a greater nematode abundance dominated by coloniser communities, indicating increased availability of resources. Implications. Results reveal the importance of integrating biological information in performance index determinations for improving soil management decisions, suggesting these relationships as sensitive bio-indicators of soil health.

Automated summary

Orchard floor management practices significantly impact soil free-living nematode communities and trophic diversity, with an increase in soil moisture, organic matter, and water-holding capacity under plant cover. Changes in nematode feeding group structure suggest shifts in soil carbon pool type and availability.