The Impact of Using Compost, Vermicompost and Mineral Fertilization on Soil Nematode Communities and Maize Grain Quality in a Pot Experiment

A pot experiment was carried out to evaluate the effects of composts, vermicomposts, and mineral fertilization on maize (Zea mays L.) growth, grain quality, soil chemical properties, and nematode communities. Eight treatments were tested, including organic amendments combined with mineral nitrogen, exclusive mineral fertilization, and an unfertilized control. Soil chemical properties, including pH, salinity, nitrogen compounds, and macro- and microelements, varied notably across treatments. Nematode community analysis revealed distinct patterns among treatments: Shannon diversity was moderate and relatively stable across most treatments, but a statistically significant reduction was recorded in treatment 7. In contrast, the Plant Parasitic Index (PPI) varied significantly, reflecting differences in community maturity and parasitic pressure. Bacterivores and fungivores indicated active nutrient cycling, while omnivores and predators reflected soil food web stability. Fertilization treatments significantly affected maize grain development. The highest thousand-kernel weight (TKW) was recorded in treatment 6 (+8.9% vs. control) and treatment 4 (+7.4% vs. control). The kernel number per cob was greatest in treatments 4 and 5 (+38% and +32%), with corresponding increases in grain mass per cob (+48% and +40%). The mean cob core weight ranged from 20.1 g in the control treatment to 30.2 g in treatment 1. The greatest increases compared to the control were observed in treatments 1 and 5, amounting to 50.2% and 44.8%, respectively. Overall, fertilization influenced grain quality, soil chemistry, and nematode communities, highlighting the importance of integrating organic and mineral amendments for sustainable crop production.