Assessment of Nematode Community Structure as a Bioindicator of Soil Health in Intensively Managed Crop Field

Abstract

Nematode community structure was assessed in intensively managed crop fields to evaluate its effectiveness as a bioindicator of soil health. Soil samples were collected from multiple agricultural sites subjected to varying fertilizer and pesticide regimes. Nematode extraction and identification were performed to trophic and functional groups, and ecological indices such as Shannon diversity index, Maturity Index (MI), Enrichment Index (EI), and Structure Index (SI) were calculated. Results indicated a dominance of bacterivorous and plant-parasitic nematodes in highly disturbed soils, while relatively balanced trophic structure with higher proportions of omnivores and predators was observed in less intensively managed fields. Reduced MI and SI values in intensively cultivated soils reflected soil food web simplification and ecological stress. In contrast, higher EI values in nutrient-enriched plots suggested increased resource-driven opportunistic communities. Multivariate analyses demonstrated strong correlations between management intensity and nematode assemblage composition, confirming sensitivity of nematode communities to agrochemical inputs. The study highlights nematodes as reliable indicators for assessing soil ecological condition and detecting early signs of degradation in agroecosystems. Integration of nematode-based indices into soil monitoring frameworks can support sustainable crop management practices by providing rapid and cost-effective evaluation of soil health status. These findings reinforce the utility of nematode assemblages as sensitive ecological tools for guiding precision agriculture and long-term soil productivity management.