The microbial community, nutrient supply and crop yields differ along a potassium fertilizer gradient under wheat–maize double-cropping systems

作者：Zeli Li, Fuli Fang, Liang Wu, Feng Gao, Mingyang Li, Benhang Li, Kaidi Wu, Xiaomin Hu, Shuo Wang, Zhanbo Wei, Qi Chen, Min Zhang, Zhiguang Liu · 发表于：Journal of Integrative Agriculture · 年份：2024 · DOI：10.1016/j.jia.2024.01.031 · 被引用次数：10 · 研究领域：Agronomic Practices and Intercropping Systems、Soil Carbon and Nitrogen Dynamics、Agricultural Innovations and Practices

Soil microorganisms play critical roles in ecosystem function. However, the relative impact of the potassium (K) fertilizer gradient on the microbial community in wheat‒maize double-cropping systems remains unclear. In this long-term field experiment (2008-2019), we researched bacterial and fungal diversity, composition, and community assemblage in the soil along a K fertilizer gradient (in the wheat season: K0, no K fertilizer; K1, 45 kg ha−1 K2O; K2, 90 kg ha−1 K2O; K3, 135 kg ha−1 K2O; and in the maize season: K0, no K fertilizer; K1, 150 kg ha−1 K2O; K2, 300 kg ha−1 K2O; K3, 450 kg ha−1 K2O) using bacterial 16S rRNA and fungal ITS data. We observed that environmental variables (such as mean annual soil temperature (MAT) and precipitation, available K, ammonium, nitrate, and organic matter) impacted the soil bacterial and fungal communities, and their impacts varied with fertilizer treatments and crop species. Furthermore, the relative abundance of bacteria involved in soil nutrient transformation (phylum Actinobacteria and class Alphaproteobacteria) in the wheat season was significantly increased compared to the maize season, and the optimal K fertilizer dosage (K2 treatment) boosted the relative bacterial abundance of soil nutrient transformation (genus Lactobacillus) and soil denitrification (phylum Proteobacteria) bacteria in the wheat season. The abundance of the soil bacterial community promoting root growth and nutrient absorption (genus Herbaspirillum) in the maize...