Effects of maize pre-cultivation on soil deterioration indicated by the soil nematode community in replanted apple orchard

Maize pre-cultivation was hypothesised to alleviate soil deterioration in replanted apple orchard, and this would be expected to be reflected in the nematode community in the soil. To test this hypothesis, soil parameters and nematode population composition were measured. Compared with replanted apple treatment, soil pH, soil organic matter, ammonium nitrogen and the available P and K content of the soil were enhanced after maize pre-planting cultivation. Maize pre-cultivation increased bacterivorous nematode populations and decreased herbivorous nematode populations, mainlyPratylenchus,ParatylenchusandTylenchusspp.The Shannon-Weaver diversity index (H ') and the richness (SR) of the nematode population, the Wasilewska functional index (WI) (soil health index) and the maturity index (MI) were increased at the flowering stage after 2-year maize pre-planting treatment, andWIwas increased at the maturity stage compared with replanted apple treatment. These results indicate that maize pre-cultivation can alleviate soil acidification and deterioration of the physicochemical properties of soil and improve soil health, food web stability and soil ecosystem sustainability in replanted apple orchard. These changes are accompanied by changes in the soil nematode communities.