微生物菌肥对退化高寒草甸地上生物量和土壤理化性质的影响

本研究以青海省贵南县退化高寒草甸为对象，评估了富含乳酸菌和醋酸杆菌的微生物菌肥在不同的添加梯度（150 mL·m^-2，200 mL·m^-2和250 mL·m^-2）下对高寒退化草甸地上植被生物量和土壤理化性质的影响。研究发现：地上植被的生物量随着微生物菌肥施用量和施用时间的增加整体上呈增加趋势，最大值均出现在施用量为200 mL·m^-2的处理，分别为192.32 g·m^-2（2017年），191.76 g·m^-2（2018年）和202.68 g·m^-2（2019年），菌肥施用处理第三年的地上植被生物量比对照高184.24%；土壤有机碳（Total organic carbon，TOC）和全氮（Total nitrogen，TN）含量在0~10 cm土壤表层中均在施用量为200 mL·m^-2处理达到最大，在10~20 cm土层中，TOC和TN在菌肥施用量为250 mL·m^-2时增加至37.49 g·kg^-1和3.32 g·kg^-1；土壤铵态氮含量在微生物菌肥施用前两年显著增加而后下降，而硝态氮含量在施用第三年显著增加。土壤有效磷含量随施用量和施用时间的增加整体上呈增加趋势。结果表明富含乳酸菌和醋酸杆菌的微生物菌肥在退化高寒草地修复中具有改善土壤理化性质的潜力。

Effects of Microbial Fertilizer on Aboveground Biomass and Soil Physiochemical Properties of Degraded Alpine Meadow

This study took the degraded alpine meadow in Guinan County, Qinghai Province, as the object to evaluate the effects of different application gradients (150 mL·m^-2, 200 mL·m^-2and 250 mL·m^-2) of microbial fertilizer rich in lactic acid bacteria and acetobacter aceti on aboveground biomass and soil physicochemical properties of degraded alpine grassland. Results showed that the aboveground biomass of vegetation increased significantly with the increase of the application amount and time of microbial fertilizer, and increased up to 184.24% in the third year compared with the control. In 0~10 cm soil layer, soil organic carbon (TOC) and total nitrogen (TN) increased with the increase of microbial fertilizer. In the 10~20 cm soil layer, TOC and TN showed a significant increase only when the application amount of bacterial fertilizer was 250 mL·m^-2, reaching 37.49 g·kg^-1 and 3.32 g·kg^-1, respectively. Soil ammonium nitrogen increased significantly in the first two years and then decreased, while nitrate-nitrogen content increased significantly in the third year, reaching 18.25 mg·kg^-1 at 250 mL·m^-2 microbial fertilizer application. Soil available P content increased significantly with the increase of application rate and time. It indicated that microbial fertilizer had the potential to improve soil physicochemical properties in the restoration of degraded alpine grassland.