Chemical fertilizer reduction combined with organic materials enhances nematode community structure stability

In this study, we conducted a field experiment to investigate the effect of reduced chemical fertilizer and combined application of organic materials on nematode community in a wheat-maize cropping system over two crop seasons (wheat and maize). The results showed that the soil moisture emerged as the major determinant of nematode community structure in wheat season, while the soil pH was the main factor influencing the nematode variation in maize season. The effect of soil properties accounted for 2.4% of the total variation in nematode community. The Shannon index in the straw addition treatment significantly increased by 38.5% in comparison with the NPK treatment in wheat season. The ecological network showed that organic fertilizer simplified the complexity of the ecological network of straw treatment and the separate return of straw suppressed the efficiency of material circulation, energy flow, and information transmission among nematode network species. These results indicate that reduced chemical fertilizer and combined application of organic materials made the nematode community structure more stable and improved the sustainability of agroecosystems.