The impact of different organic fertilizers on the soil nematode assemblages in an organic apple orchard

Summary

A trial testing different regionally available organic fertilizers (vinassa, clover pellets, horn shavings, biodigestate and manure) was established in 2018 in an organic apple orchard and their effect on soil nematodes biodiversity was assessed by determining the composition
of trophic groups and calculating some diversity indexes. Microbial feeding nematodes reacted rapidly to introduction of organic fertilizers due to the likely stimulation of bacteria and fungi activity. Manure induced the highest increase in bacteria feeders and Vinassa on fungal feeders and omnivores. The biodigestate promoted the plant feeders. Considering the biodiversity indexes, the greatest maturity and structure indexes were found in soil fertilized with Vinassa and biodigestate, while the lowest resulted in soil fertilized with horn shavings and manure. The different characteristics of the applied fertilizers (e.g. physical
status, N mineralization rate, nutrient content, etc.) could be taken into consideration when assessing the effect on individual trophic groups of soil nematodes and on their community composition.