Effective microorganisms (EM) might alleviate deterioration of soil environmental quality and yield decline of pepper (Capsicum annuum) caused by continuous replanting and imbalanced fertilizer application in Xinjiang. We investigated the effects of applying EM microbial agent on the growth of pepper plants, yield, soil nutrient content, soil enzyme activity, and rhizosphere eukaryotic community. The results showed that the application of EM microbial agent increased plant height, stem diameter, leaf length, leaf width and root length by 22.6%, 35.3%, 33.3%, 29.7% and 15.1%, respectively. It also increased fruit width, individual fruit weight, and yield by 5.3%, 42.9%, and 74.7%, respectively. After the application of EM microbial agent, the levels of soil available nitrogen increased by 10.2% and 5.8% during the flowering and maturity stages, respectively. Similarly, available phosphorus increased by 10.4% and 13.4%, respectively. The soil sucrase activity was increased by 40.7%, 14.6%, and 9.3% during the seedling, flowering, and maturity stages, respectively. Urease activity was also increased by 7.9%, 10.2%, and 11.5%, respectively. Furthermore, the application of EM microbial agent increased soil peroxidase activity by 16.8% and 44.6% at flowering and maturity stages, respectively. The application of microbial agent significantly altered the β-diversity of the rhizosphere eukaryotic community in pepper plants. Specifically, microbial agent increased the relative abundances of populations belonging to Enchytraeus and Sminthurides genera, which could contribute to soil improvement and nutrient cycling. Compared to the CK, the relative abundance of pathogenic microorganisms including Olpidium and Aplanochytrium genera decreased by 98.0% and 89.3%, and the relative abundance of the Verticillium decreased to 0. These results demonstrated that EM microbial agent could increase soil nutrient content, enhance soil enzyme activity, and reduce soil pathogenic fungi in the pepper cultivation areas of Xinjiang, thus achieving beneficial effects on pepper growth and fruit yield.
有效微生物(EM)复合菌剂可缓解新疆连年重茬种植与偏施化肥导致的辣椒土壤环境质量恶化、产量下降等问题。本研究以不施EM复合菌剂为对照(CK),研究施用EM复合菌剂对辣椒植株生长、产量、土壤养分含量、土壤酶活性和根际真核生物群落结构的影响。结果表明: 与CK相比,施用EM复合菌剂的辣椒株高、茎粗、叶长、叶宽和根长分别增加22.6%、35.3%、33.3%、29.7%和15.1%,果宽、单个果重和产量分别提升5.3%、42.9%和74.7%。施用EM复合菌剂的土壤碱解氮在花期和成熟期分别提高10.2%和5.8%,速效磷分别提高10.4%和13.4%。施用EM复合菌剂的土壤蔗糖酶活性在苗期、花期和成熟期分别提高40.7%、14.6%和9.3%,脲酶活性分别提高7.9%、10.2%和11.5%,过氧化物酶活性在花期和成熟期分别提高16.8%和44.6%。施用EM复合菌剂还显著改变了辣椒根际真核生物群落的β多样性,其中,具有改良土壤、促进土壤养分循环功能的线蚓属和Sminthurides属种群的相对丰度较高,而致病微生物油壶菌属和不动壶菌属种群的相对丰度分别较CK降低了98.0%和89.3%,轮枝孢属种群的相对丰度降为0。表明EM复合菌剂能够提高新疆地区辣椒土壤养分含量和酶活性,减少土壤致病真菌,从而达到促进辣椒生长、提高果实产量的效果。.
Keywords: effective microorganisms; pepper growth; rhizosphere eukaryotes; soil nutrients; yield.