Context

Soil bacterial community critical for sustaining the ecosystem is sensitive to long-term cultivation, including fertilizer applications. Although have been a lot of controlled-release potassium chloride (CRK) studies, maybe those on soil bacterial ecology related to potassium use efficiency (KUE) and yield are very limited.

Objectives

We investigated how different proportions of CRK affected soil bacterial diversity and community structure, carbon/nitrogen cycle enzyme levels, soil nutrient supply, and maize (Zea mays L.) yield.

Methods

An eight-year (2014–2021) field experiment using different proportions (0%, 50% and 100%) of CRK at 113 kg K₂O ha⁻¹ was conducted to determine the optimal fertilization method.

Results

Increasing the percentage of CRK boosted the diversity and abundance of the bacteria (Bacillus, Gaiella, and Sphingomonas) associated with the carbon and nitrogen cycle enzymes. It also enhanced the interaction intensity between taxa, as slow nutrient release led to taxa with comparable ecological niches coexisting and collaborating to decrease functional redundancy. Increased CRK improved soil fertility significantly, enhanced the composition and function of soil bacterial colonies, and explained 82.8% of the variation in the bacterial colonies; directly increased soil nitrogen cycling enzymes content and the bacterial community relative abundance, and indirectly increased soil nutrient supply by 7.1–38.6%, maize yield by 11.7–11.8% and KUE by 8.4–13.2% points.

Conclusions

The higher percentage of CRK significantly enhanced the stability of soil bacterial ecology, improved soil available potassium, ammonium, nitrate, soluble nitrogen contents, and organic matter content, and increased maize yield and KUE.

Implications

Long-term CRK application is a good regime to improve maize yield and KUE by regulating soil bacterial biodiversity, carbon/nitrogen cycle enzyme activities, and soil nutrient supply.

中文翻译：

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长期施用控释氯化钾通过影响土壤细菌生态、酶活性和养分供应来提高玉米产量

语境

对维持生态系统至关重要的土壤细菌群落对长期种植很敏感，包括施肥。尽管已经有很多控释氯化钾（CRK）的研究，但可能与钾利用效率（KUE）和产量相关的土壤细菌生态学研究非常有限。

目标

我们研究了不同比例的 CRK 如何影响土壤细菌多样性和群落结构、碳/氮循环酶水平、土壤养分供应和玉米 ( Zea mays L.) 产量。

方法

_{使用不同比例（0%、50% 和 100%）的 CRK 在 113 kg K 2} O ha ⁻¹下进行为期八年（2014-2021）的田间试验以确定最佳施肥方法。

结果

增加 CRK 的百分比可提高细菌的多样性和丰度（芽孢杆菌属、盖氏菌属和鞘氨醇单胞菌属）) 与碳和氮循环酶有关。它还增强了类群之间的相互作用强度，因为缓慢的养​​分释放导致具有可比生态位的类群共存和协作以减少功能冗余。CRK的增加显着提高了土壤肥力，增强了土壤菌落的组成和功能，解释了82.8%的菌落变异；直接增加土壤氮循环酶含量和细菌群落相对丰度，间接增加土壤养分供应7.1-38.6%，玉米产量增加11.7-11.8%，KUE增加8.4-13.2%点。

结论

较高比例的CRK显着增强了土壤细菌生态的稳定性，提高了土壤有效钾、铵、硝酸盐、可溶性氮含量和有机质含量，提高了玉米产量和KUE。

启示

长期施用 CRK 是通过调节土壤细菌生物多样性、碳/氮循环酶活性和土壤养分供应来提高玉米产量和 KUE 的良好机制。