The Mixed Addition of Biochar and Nitrogen Improves Soil Properties and Microbial Structure of Moderate–Severe Degraded Alpine Grassland in Qinghai-Tibet Plateau

Abstract

The degradation of the grassland system has severely threatened the safety of the ecological environment and animal husbandry. The supplement of key substances lost due to degradation is widely used to accelerate the restoration of the degraded grassland ecosystem. In this study, we investigated the effects of biochar and nitrogen addition on soil properties and microorganisms of degraded alpine grassland. The experimental treatments consisted of the control without any addition, only nitrogen addition (10 gN/m2), only biochar addition (4.00 kg/m2 biochar), and the mixed addition of biochar and nitrogen (4.00 kg/m2 biochar and 10 gN/m2 nitrogen, respectively). Adding N alone did not significantly change the pH, total organic carbon (TOC), total nitrogen (TN), microbial biomass (MB), and the composition proportion of microbes of the soil, but increased the contents of soil water content (SWC), NH4+-N, NO3–-N, available phosphorus (AP), and the biomass of bacteria and fungi. The addition of biochar or the mixture of biochar and nitrogen increased the contents of pH, TOC, TN, MB, SWC, NH4+-N, NO3–-N, AP, bacteria, and fungi in the soil and changed the structure of the soil microbial community. The increasing intensity of AP, bacteria, and fungi under the addition of biochar or the mixture of biochar and nitrogen was significantly greater than that under N addition alone. These results indicated that the separated addition of nitrogen and biochar and the mixed addition of biochar and nitrogen all improved the soil condition of the moderate–severe degraded alpine grassland, but the mixed addition of biochar and nitrogen could be a better strategy to remediate the degraded alpine grassland.

Effective microorganisms input efficiently improves the vegetation and microbial community of degraded alpine grassland

“…Additionally, a positive correlation occurred between a majority of the environmental factors and ectomycorrhizal fungi and saprophytic fungi. This suggested that ectomycorrhizal and saprophytic fungi were particularly vulnerable to soil environments alterations in comparison to other indicator microorganisms, and they possessed a competitive edge ( Li et al, 2021 ). The Mantel test revealed a significant correlation between NH 4 + -N and different microbial communities.…”

“…The climate of experimental region is typical plateau continental climate with mean annual temperature of 2.3°C and mean annual precipitation of 403.80 mm. The annual evaporation is 1378.5 mm ( Li et al, 2021 ). The main plants in the experimental site include Poa crymophila , Cleistogenes squarrosa , Carex tristachya , Elymus nutans .…”

Response of bacterial community characteristics in the rhizosphere soil of Stellera chamaejasme L. to its expansion on the Qinghai‐Tibet Plateau

“…The grasslands at Tibetan Plateau are vulnerable to damage due to short plant growth periods, harsh climate, and weak ecosystem resistance (Liu et al, 2018). The degradation of grassland thus will lead to severe ecosystem imbalance (Li et al, 2021), such as the decrease of vegetation biodiversity (Dong et al, 2013), loss of soil fertility (Hopping et al, 2018), and reduction of grassland productivity and ecological function diversity (Peng et al, 2018).…”

Spatialization method of monitoring grazing intensity: A case‐study of the Tibet Selinco basin, Qinghai‐Tibet Plateau

“…In the Qinghai‐Tibet Plateau, the main ecosystem is the alpine steppe ecosystem, which stores a large amount of carbon and plays an important role in the global carbon cycle (Li, Zhao, et al, 2021; Liu et al, 2016; Ni, 2002). The primary form of resource utilization in alpine grasslands on the Tibetan Plateau is grazing, which plays a dominant role in maintaining local livestock production and the sustainable development of pastures (Guo, Wen, et al, 2021; Li, Liu, et al, 2021).…”