Aims

The carbon–nitrogen ratio (C/N ratio) of straw significantly influences its mineralization and nutrient release when returned to the soil. However, little is known about the effects of different mixtures of different types of straw on straw mineralization, dynamic changes of soil properties, soil microbial communities and the growth of later maize.

Methods

This study was conducted through incubation and pot experiments, with 12 g/kg straw. Design of treatments included: (1) maize straw return (M), (2) soybean straw return (S), (3) 1:1 ratio of maize straw and soybean straw return (MS), (4) 2:1 ratio of maize straw to soybean straw return (2MS), (5) maize straw return combined with nitrogen fertilizer (MF) and (6) no straw return (NS).

Results

Compared with M treatment, MS and MF treatment enhanced the straw mineralization rate and nutrient release, thus increasing the biomass of succeeding maize. The MS treatment increased the relative abundance of Chloroflexi, Acidobacteriota, and Proteobacteria by 15.54%, 5.36%, and 14.29%, respectively, compared to the M treatment. Straw return treatments significantly decreased the prevalence of the pathogenic fungus Fusarium compared to the NS approach. Correlation analyses indicated a positive association between soil chemical properties and the presence of Proteobacteria, Firmicutes, Bdellovibrionota, and Nitrospirota. Conversely, these factors showed a negative correlation with Actinobacteriota, Gemmatimonadota, Funneliformis, Trichoderma, and Fusarium.

Conclusion

In summary, the combined addition of soybean straw and maize straw in a 1:1 ratio optimizes the microbial community, enhances soil nutrient cycling, improves soil fertility, and positively affects maize biomass and nutrient uptake.

中文翻译：

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通过添加大豆秸秆改变微生物群落结构促进玉米秸秆降解率

 目标

秸秆的碳氮比 （C/N ratio） 显着影响其返回土壤时的矿化和养分释放。然而，关于不同类型秸秆的不同混合物对秸秆矿化、土壤性质的动态变化、土壤微生物群落和晚熟玉米生长的影响，人们知之甚少。

 方法

本研究通过培养和盆栽实验进行，秸秆含量为 12 g/kg。处理设计包括：（1） 玉米秸秆还田 （M），（2） 大豆秸秆还田 （S），（3） 玉米秸秆与大豆秸秆还田比例 （MS） 1：1，（4） 玉米秸秆与大豆秸秆还田比例 （2MS），（5） 玉米秸秆还田配氮肥 （MF） 和 （6） 无秸秆还田 （NS）。

 结果

与 M 处理相比，MS 和 MF 处理提高了秸秆矿化速率和养分释放，从而提高了后续玉米的生物量。与 M 处理相比，MS 处理使 Chloroflexi、Acidobacteriota 和 Proteobacteria 的相对丰度分别提高了 15.54% 、 5.36% 和 14.29%。与 NS 方法相比，秸秆还田处理显著降低了病原真菌镰刀菌的流行率。相关性分析表明，土壤化学性质与变形菌门、厚壁菌门、Bdellovibrionota 和 Nitrospirota 的存在呈正相关。相反，这些因素与放线杆菌门、Gemmatimonadota、Funneliformis、木霉属和镰刀菌呈负相关。

 结论

综上所述，大豆秸秆和玉米秸秆以 1：1 的比例联合添加可优化微生物群落，增强土壤养分循环，提高土壤肥力，并对玉米生物量和养分吸收产生积极影响。