Soil properties and plants influence soil microbial community diversity, and their role in nutrient cycling could influence plant productivity; however, it is not clear the relationships between soil bacterial communities, soil moisture, and nitrogen (N) content, and whether these associations influence plant productivity. In this study, we investigated how the soil microbial community affects root zone productivity in winter wheat. We also verified whether productivity can be improved by water adjustment and N management in drip irrigation field experiments (I0, natural condition; I1, jointing to heading stage S1 55%–80%θ_f, field capacity, anthesis to mature stage S2 70%–80%θ_f; I2, S1 55%–90%θ_f, S2 70%–90%θ_f; and I3, S1 55%–100%θ_f, S2 70%–100%θ_f) and under different N application rates (N0, N1, N2, and N3 represent 0, 150, 200, and 250 kg N ha⁻¹). Soil moisture and N application rate significantly influenced water use efficiency (WUE), N use efficiency (NUE), yield, and soil bacterial abundance and diversity in the wheat root zone. N application decreased the richness indices in un-irrigated soils (I0), whereas it initially increased, and then decreased the indices in irrigated soils (I1, I2, and I3). The primary factor influencing the dominant bacterial taxa was soil moisture content (SMC), followed by root length density (RLD). The root system and soil bacterial diversity strong influenced wheat yield. The I1N1 treatment resulted in the highest root weight density (RWD), WUE, and NUE, and thus increased wheat yield; furthermore, it had the least influence on the diversity of soil bacteria. Our work suggests that the response of bacterial communities to soil moisture and nitrogen content largely regulates crop production in agro-ecosystems, and that regulating soil moisture and nitrogen fertilizer use may provide a sustainable solution for maintaining farmland productivity.

中文翻译：

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土壤水分和氮含量通过对滴灌根系和土壤细菌多样性的影响来影响小麦产量

土壤性质和植物影响土壤微生物群落多样性，它们在养分循环中的作用会影响植物生产力；然而，目前尚不清楚土壤细菌群落、土壤水分和氮 (N) 含量之间的关系，以及这些关联是否影响植物生产力。在这项研究中，我们调查了土壤微生物群落如何影响冬小麦根区生产力。我们还验证了滴灌田间试验中是否可以通过调水和施氮来提高生产力（I0，自然条件；I1，拔节至抽穗期 55%–80%θ _f，田间持水量，开花至成熟期 S2 70% –80%θ _f ; I2, S1 55%–90%θ _f , S2 70%–90%θ _f ; 和 I3, S1 55%–100%θ_f , S2 70%–100%θ _f ) 和在不同施氮量下（N0、N1、N2 和 N3 代表 0、150、200 和 250 kg N ha ^-1）。土壤水分和施氮量显着影响小麦根区水分利用效率（WUE）、氮利用效率（NUE）、产量以及土壤细菌丰度和多样性。施氮降低了未灌溉土壤的丰富度指数（I0），而在灌溉土壤（I1、I2 和 I3）中它最初增加，然后降低了指数。影响优势细菌分类群的主要因素是土壤水分含量 (SMC)，其次是根长密度 (RLD)。根系和土壤细菌多样性强烈影响小麦产量。I1N1 处理导致最高的根重密度 (RWD)、WUE 和 NUE，从而增加了小麦产量；此外，它对土壤细菌多样性的影响最小。