Tea seed meal application promoted microbial community diversity in the soil of peach orchard

Soil microbes are indispensable in agricultural production, and they respond differently to different fertilization regimes. However, there is limited understating of microbial composition and function responses to an organic fertilizer tea seed meal (TSM) and conventional fertilizer. Here we first reported the change rules and functions of soil microbial community in peach orchard soil after application of compound fertilizer plus urea (CFU) and different amounts (1.25, 2.50, 3.75 and 5.00 kg) of TSM. Compared to CFU, the application of 1.25, 2.50 and 3.75 kg TSM significantly decreased the Chao1 index of bacterial community in peach orchard soil. The Shannon index of bacterial and fungal communities in 2.50 kg TSM treatment was significantly higher than that in CFU. Beta diversity analysis of bacteria and fungi (based on Bray-Curtis matrix and OTUs level) revealed significant structural differences among all five experimental groups (ANOSIM, bacteria: R= 0.665, p = 0.001; fungi: R= 0.996, p = 0.001). The TSM treatments significantly decreased the relative abundances of potentially unfriendly bacteria (Acidothermus, Acidicaldus, Sphingomonas, Candidatus Koribacter and Candidatus Solibacter) and fungi (Fusarium), and significantly increased the relative abundances of potentially beneficial fungi (Trechispora, Sagenomella, Penicillium, Acaulium caviariforme, Leucoagaricus and Chlorophyllum) compared with CFU. These changes were more obvious when the application amount of TSM was 2.50 kg. This study provides insights into the potential of application of TSM as an organic fertilizer in agricultural production.

土壤微生物在农业生产中不可或缺，且对不同施肥模式呈现出差异化响应。然而，目前学界对于有机肥茶籽饼（tea seed meal, TSM）及常规肥料驱动下的土壤微生物组成与功能响应，认知仍较为有限。本研究首次阐明了施用复合肥配施尿素（compound fertilizer plus urea, CFU）及不同梯度用量（1.25、2.50、3.75与5.00 kg）的TSM后，桃园土壤微生物群落的变化规律与功能特征。与CFU组相比，施用1.25、2.50及3.75 kg的TSM可显著降低桃园土壤细菌群落的Chao1指数。2.50 kg TSM处理组中，细菌与真菌群落的Shannon指数均显著高于CFU组。基于Bray-Curtis距离矩阵与操作分类单元（Operational Taxonomic Unit, OTU）水平的细菌、真菌Beta多样性分析显示，5个实验组的群落结构均存在显著差异（相似性分析ANOSIM：细菌组R=0.665，p=0.001；真菌组R=0.996，p=0.001）。与CFU组相比，TSM处理组显著降低了潜在有害细菌（Acidothermus、Acidicaldus、Sphingomonas、Candidatus Koribacter及Candidatus Solibacter）与真菌（Fusarium）的相对丰度，并显著提升了潜在有益真菌（Trechispora、Sagenomella、Penicillium、Acaulium caviariforme、Leucoagaricus及Chlorophyllum）的相对丰度；当TSM施用量为2.50 kg时，上述变化趋势更为显著。本研究为茶籽饼有机肥在农业生产中的应用潜力提供了理论参考。