The growing resistance of weeds to herbicides demands innovative strategies that harness soil biology for effective weed control. We examined the use of carbon amendments to stimulate microbial immobilization of soil nitrogen for weed control. We hypothesized that increased carbon availability will stimulate soil microbial growth, leading to greater nitrogen immobilization, which consequently decreases plant-available nitrogen and suppresses the growth of nitrogen-responsive weed species. We buried 80 19-L pots in a research farm field and added sawdust and sucrose to soils as a high carbon treatment and used unamended soils as a control. We examined eight different weed species separately, and measured plant growth, soil carbon, available nitrate, microbial carbon and nitrogen, and microbial community composition after 11 weeks of treatment. The carbon amendments altered plant-microbial competition for nitrogen, resulting in reduced biomass for most weed species. The carbon-amended soils had higher microbial biomass carbon and nitrogen, slower nitrogen cycling, and less available soil nitrogen, indicating enhanced nitrogen immobilization. The carbon treatment altered the beta diversity of soil fungi and bacteria and reduced fungal alpha diversity estimated by the Shannon index. The study results indicate that high carbon substrates can be used to modify plant-microbial competition for soil nitrogen with important implications for developing sustainable weed management practices.

中文翻译：

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操纵土壤资源可用性来改变微生物群落，以实现农业生态系统中的杂草管理


杂草对除草剂的抗药性不断增强，需要利用土壤生物学来有效控制杂草的创新策略。我们研究了使用碳改良剂来刺激土壤氮的微生物固定以控制杂草。我们假设，碳有效性的增加将刺激土壤微生物的生长，导致更多的氮固定，从而减少植物有效氮并抑制氮响应性杂草物种的生长。我们在一个研究农田中埋了 80 个 19 升的盆，并向土壤中添加了锯末和蔗糖作为高碳处理，并使用未改良的土壤作为对照。我们分别检测了八种不同的杂草种类，并在处理 11 周后测量了植物生长、土壤碳、有效硝酸盐、微生物碳和氮以及微生物群落组成。碳修正改变了植物与微生物对氮的竞争，导致大多数杂草物种的生物量减少。碳改良土壤具有较高的微生物生物量碳和氮、较慢的氮循环和较少的可用土壤氮，表明氮固定化增强。碳处理改变了土壤真菌和细菌的β多样性，并降低了香农指数估计的真菌α多样性。研究结果表明，高碳基质可用于改变植物与微生物对土壤氮的竞争，对制定可持续杂草管理实践具有重要意义。