Excessive nitrogen (N) fertilization in croplands results in environmental problems, such as soil quality deterioration, water contamination, and biodiversity losses, which threaten the sustainable development of soil ecosystems. The soil nematode food web plays key roles in soil organic matter decomposition and nutrient cycling, and thus the sustainable development of cropland ecosystems. However, how the negative impact from the excessive N fertilization on the nematode food web is effectively alleviated remains uncertain. This study aimed to explore the effects of different N fertilization management practices (N fertilizer reduction or organic material addition) on alleviating the negative effects on the nematode food web in croplands. Four treatments/ management practices were examined: conventional fertilization (N control), N fertilizer reduction of 100% (N₀), N fertilizer reduction of 50% (N₁), and conventional fertilization with organic material addition (N_+S). The results showed that the abundance of nematodes and microbial phospholipid fatty acids (PLFAs) both increased in the treatments of N₀, N₁, and N_+S compared with N. Besides, N_+S also increased the nematodes' biomass, diversity, and metabolic footprint, which correspondingly strengthened the nutrient turnover through the nematode food web. Overall, two management practices 1)N fertilizer reduction and 2) organic material addition, differ in the abiotic or biotic process in alleviating the negative effects of N fertilization on the nematode food web. The reducing N fertilization can directly alleviate the negative effect of fertilizer on soil acidification and then benefit for the growth of microorganisms and nematodes. The exogenous carbon input from organic material addition might promote carbon flowing and immobilization into nematode food web, and ultimately enhance the stability of soil food web.

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探索减少氮肥和添加有机物质的做法：研究其对农田线虫食物网的缓解作用

农田中过量施氮会导致环境问题，例如土壤质量恶化，水污染和生物多样性丧失，从而威胁到土壤生态系统的可持续发展。土壤线虫食物网在土壤有机质的分解和养分循环中起着关键作用，从而在农田生态系统的可持续发展中起着关键作用。然而，如何有效减轻过量施氮对线虫食物网的负面影响仍然不确定。这项研究旨在探讨不同的氮肥管理措施（减少氮肥或添加有机物质）对减轻农田中线虫食物网的负面影响。检查了四种处理/管理方法：常规施肥（氮肥控制），₀），减少50％的氮肥（N ₁），并添加有机材料进行常规施肥（N _{+ S}）。结果表明，线虫的丰度和微生物磷脂脂肪酸（磷脂脂肪酸）中的N的处理既增加了₀，N ₁和N _{+ S}与N.相比此外，N _{+ S}还增加了线虫的生物量，多样性和代谢足迹，从而相应地通过线虫食物网增强了养分的转化。总体而言，两种管理措施1）减少氮肥和2）添加有机物质在缓解氮肥对线虫食物网的负面影响方面，在非生物或生物过程中有所不同。减少氮肥的施用量可以直接减轻肥料对土壤酸化的负面影响，进而有利于微生物和线虫的生长。有机物添加产生的外源碳输入可能促进碳的流动和固定到线虫食物网中，并最终增强土壤食物网的稳定性。