Response of pasture vegetation communities and soil carbon and nitrogen in Hulunbuir to different restoration measures

In order to improve the phenomenon of pasture degradation，fencing and sealing，application of farmyard manure，mechanical perforation and other means of restoration have been adopted for grazing land．The response patterns of grassland vegetation communities and soil nutrients were explored under the adoption of different restoration methods，and the effects of the implementation of these measures were further compared and analysed．This study used the degraded pasture in Chenbalhu banner，Hulunbeier city，Inner Mongolia autonomous region as the experimental site，and the following four measures were carried out in 2023：control（CK），fencing（WF），farmyard manure（NJF），mechanical aerator +  farmyard manure（DNJF）．In August 2023，plant and soil surveys were conducted to assess the effects of short-term restoration effects on plant community characteristics，biodiversity and soil carbon and nitrogen nutrients．Under WF，NJF and DNJF treatments，the vegetation cover，density and aboveground biomass were significantly higher than that of CK，and the enhancement effect of community height and aboveground biomass of NJF treatment was particularly significan（t P<0.05），with a 110.6% increase compared to the CK．WF，NJF and DNJF treatments effectively enhanced the plant diversity of the degraded grazing land，and the diversity enhancement of WF treatment was the most significant．All restoration treatments promoted the growth of perennial grasses，and NJF treatment elevated the aboveground biomass of the C4 plants，thus enhancing the light use efficiency of the vegetation community．DNJF treatment had a better effect on increasing soil organic carbon and total nitrogen content in grazing land than WF and NJF treatments．The soil organic carbon content in the 0-15 cm of DNJF treatment was 17.62 g/kg，with an increase of 29.64%，compared to CK．The correlation analysis results indicated that DNJF treatment enhanced the positive correlation between vegetation communities and soil nutrients．The three methods of fencing，farmyard manure and mechanical perforation + application of farmyard manure all had significant restoration effects on degraded pasture．Fencing significantly enhanced plant diversity，application of farmyard manure significantly increased grassland productivity，and mechanical aerator effectively improved soil fertility．In a comprehensive analysis，mechanical aerator + farmyard manure was the most effective for the sustainable use of degraded grazing land.