Abstract: Long-term farming has significantly degraded the soil in the northwest of Liaoning Province. Native grass planting is an effective measure to improve the soil. In this experiment,three dominant grasses were transplanted into the abandoned farmland,and soil physicochemical properties and microbial communities were compared with the adjacent woodland,farmland and abandoned land. The results showed that soil pH of Arundinella anomala grassland and Elymus kamoji grassland was significantly higher than farmland and abandoned land,and the nutrient content was significantly lower than farmland. Observed species and Chao1 indexes of soil bacteria in Elymus dahuricus grassland and Arundinella anomala grassland were significantly lower than farmland. Soil bacterial α diversity was significantly positively correlated with nitrate nitrogen content,and fungal α diversity was significantly positively correlated with nitrate nitrogen content and total phosphorus content. The relative abundance of Rhizobiales and Frankiales in the soil of Arundinella anomala grassland,Elymus kamoji grassland and Elymus dahuricus grassland was higher than farmland,the relative abundance of Gemmatimonadales was lower than farmland,and the relative abundance of Thelebolales fungi was higher than that in farmland and abandoned land. In summary,the establishment of native grassland can alleviate farmland soil acidification,optimize the microbial community structure,and promote the sustainable development of soil.

Key words: Northwest Liaoning, Native grass, Soil Physicochemical Properties, Soil bacteria, Soil fungi

摘要： 长期的耕作导致了辽西北农田土壤的严重退化。本研究以辽西北连作农田为研究对象，通过分析实验组与周边自然生境土壤理化性质和微生物群落结构差异，探讨乡土草种植对连作农田土壤的改良效果。结果表明：野古草(Arundinella anomala)草地和鹅观草(Elymus kamoji)草地的土壤pH值显著高于农田和撂荒地，养分含量显著低于农田。披碱草(Elymus dahuricus)草地和野古草草地土壤细菌的观测物种数与Chao1指数显著低于农田。土壤细菌α多样性与土壤硝态氮含量呈显著正相关关系，真菌α多样性与土壤硝态氮含量和全磷含量呈显著正相关关系。野古草、鹅观草和披碱草草地土壤细菌根瘤菌目和弗兰克氏菌目的相对丰度高于农田，芽单胞菌目的相对丰度低于农田，真菌寡囊盘菌目相对丰度高于农田和撂荒地。综上，乡土草草地建植可缓解农田土壤酸化，改善微生物群落结构，促进土壤的可持续发展。

关键词: 辽西北, 乡土草, 土壤理化性质, 土壤细菌, 土壤真菌