Data_Sheet_1_Untangling the Rhizosphere Bacterial Community Composition and Response of Soil Physiochemical Properties to Different Nitrogen Applications in Sugarcane Field.xlsx

Minimizing the use of chemical fertilizers and investigating an appropriate ecofriendly level of nitrogen fertilizer is the key to sustainable agriculture. Sugarcane is the main cash crop of China, especially in the Guangxi region. Information regarding the effect of different nitrogen levels on sugarcane rhizosphere microbiota is still limited. In this study, we evaluated the effect of four different levels of nitrogen fertilizers on rhizosphere bacterial composition using high throughput sequencing, along with soil physiochemical properties, sugarcane agronomic and yield performance. The four treatment combinations were CK (no fertilizers), L (Low, 100 kg ha–1), M (Medium, 150 kg ha–1), and H (High, 200 kg ha–1). The results showed that M nitrogen application significantly altered the rhizosphere bacterial community, soil properties, and sugarcane yield. The richness and evenness of the bacterial community were higher in M treatment than CK. In M treatment important bacterial phyla Acidobacteria and Proteobacteria increased by 47 and 71%, respectively; and at genus level, Acidothermus and Bradyrhizobium increased by 77.2 and 30.3%, respectively, compared to CK. Principal component analysis (PCA) and cluster analysis further confirmed the level of differences among the treatments. The PCA analysis explained 80% of the total variation among the treatments. Spearmen correlation heatmap showed that environmental factors such as pH, AP (available phosphorous), AK (available potassium), and SCAT (soil catalase) were the key factors impacting sugarcane rhizosphere microbiome composition. The H and L nitrogen application alter the bacterial community and sugarcane performance but the M nitrogen application appears to be ecofriendly, productive, and an appropriate nitrogen application rate that could be further used in the Guangxi region.

减量化肥施用总量、探究适配的生态友好型氮肥施用水平，是农业可持续发展的核心要义。甘蔗是我国尤其是广西地区的主要经济作物，目前针对不同氮肥水平对甘蔗根际微生物群落影响的相关研究仍较为匮乏。本研究借助高通量测序（high throughput sequencing）技术，结合土壤理化性质、甘蔗农艺性状与产量表现，探究了4种不同氮肥施用水平对甘蔗根际细菌群落组成的影响。试验共设置4个处理组：CK（空白对照，不施氮肥）、L（低氮组，施氮量100 kg·ha⁻¹）、M（中氮组，施氮量150 kg·ha⁻¹）以及H（高氮组，施氮量200 kg·ha⁻¹）。结果表明，中氮处理可显著改变甘蔗根际细菌群落结构、土壤理化性状及甘蔗产量。中氮组细菌群落的丰富度与均匀度均高于空白对照组；相较于CK，中氮组的关键细菌门类——酸杆菌门（Acidobacteria）与变形菌门（Proteobacteria）的相对丰度分别提升47%与71%；在属水平上，嗜酸放线菌属（Acidothermus）与慢生根瘤菌属（Bradyrhizobium）的相对丰度分别提升77.2%与30.3%。主成分分析（Principal Component Analysis，PCA）与聚类分析进一步验证了各处理组间的群落差异程度，该分析可解释各处理组间80%的总变异度。斯皮尔曼相关热图分析显示，pH值、有效磷（available phosphorous，AP）、有效钾（available potassium，AK）与土壤过氧化氢酶（soil catalase，SCAT）等环境因子是影响甘蔗根际微生物群落组成的关键调控因素。高氮与低氮处理均会改变细菌群落结构与甘蔗生长表现，但中氮处理兼具生态友好性与高产性，是适合广西地区推广应用的适宜氮肥施用方案。