Effects of Different Land Utilization Methods on Soil Aggregate Stability and Organic Carbon Content in Alpine Grassland
Journal Title: Bulletin of Soil and Water Conservation - Year 2023, Vol 43, Issue 1
Abstract
[Objective] The soil aggregate stability and differences in organic carbon distribution for Bayanbulak alpine grassland, Xinjiang Wei Autonomous Region under different land utilization methods were analyzed in order to provide a theoretical basis for the evaluation of soil aggregate organic carbon and other ecological functions in this region. [Methods] Three land utilization methods for an alpine grassland in Bayinbuluk were evaluated: reclamation, abandoning farming to grazing, and grazing. Soil aggregates were screened by dry screening and wet screening, mean weight diameter (MWD), geometric mean diameter (GMD), percentage of aggregate destruction (PDA), and soil organic carbon (SOC) contents of soil aggregates were measured and calculated to quantify differences in soil aggregate stability and organic carbon in an alpine grassland under different land utilization methods. [Results] ① Under the three land utilization methods, soil aggregates in an alpine grassland were primarily large aggregates (≥0.25 mm). In the subsurface (10—20 cm) soil, the PDA for the treatment of abandoning farming to grazing was significantly lower than that of the grazing treatment (p<0.05), and was not significantly different from the PDA for the reclamation treatment (p>0.05). In addition, the soil PDA values of the remaining soil layers in the treatment of abandoning farming to grazing were significantly greater than those observed for the reclamation treatment and the grazing treatment (p<0.05). In the surface layer (0—10 cm), there was no significant difference in PDA between the reclamation treatment and the grazing treatment (p>0.05). The PDA values of the other soil layers in the reclamation treatment were significantly greater than in the grazing treatment. ② The SOC content, soil aggregate organic carbon content, and the contribution rate of soil aggregates in the treatment of abandoning farming to grazing were significantly less than those in the other treatments (p<0.05). In the 0—10 cm soil layer, organic carbon content and its contribution rate of aggregates with particle size greater than 5 mm in the grazing treatment were greater than those in the reclamation treatment (27.89 g/kg, 6.34%) and the treatment of abandoning farming to grazing (36.96 g/kg, 14.3%). In the subsurface layer (10—20 cm), lower layer (20—30 cm), and deep layer (30—40 cm), the organic carbon content and contribution rate of soil aggregates with a particle size of ≥5 mm in the treatment of abandoning farming to grazing were significantly less than those in the reclamation treatment and the grazing treatment (p<0.05). ③ The mass percentage of soil aggregates and their stability were significantly correlated with SOC content (p<0.05). The mass percentage of soil aggregates ≥2 mm, MWD and GMD of soil aggregates were significantly positively correlated with SOC content (p<0.05), of which soil aggregates ≥5 mm showed a very significant positive correlation (p<0.01) with SOC content. The mass percentage of soil aggregates less than 2 mm and the stability of soil aggregates were significantly negatively correlated with SOC content (p<0.05), of which soil aggregates <1 mm were extremely significantly negatively correlated with SOC content (p<0.01). [Conclusion] Grassland reclamation activities reduced the stability of soil aggregates and their SOC contents. Soil aggregate stability and SOC content were the lowest in the treatment of abandoning farming to grazing. It is recommended that grassland should be moderately restored (fertilized, sown, etc.) after abandonment for grazing and utilization.
Authors and Affiliations
Keyi Li, Guangling Yu, Mo Chen, Maidinuer· Abulaizi, Yang Hu, Hongtao Jia
County Scale Ecological Environmental Monitoring and Evaluation Based on Spatial Information Technology
[Objective] An accurate acquisition method for ecological environmental monitoring data was studied to construct an evaluation index system of ecological environmental quality in order to provide a basis for precise prot...
Carbon Carrying Capacity Evaluation for Yibin City of Sichuan Province Based on InVEST Model Duing 2010—2020
[Objective] The basis of urban carbon carrying capacity was determined in order to provide scientific support for urban "double carbon" and low-carbon development. [Methods] Based on land use data for Yibin City, Sichuan...
Coupled Coordination of Land and Water Use Efficiency in Huaihe River Basin and Its Spatial and Temporal Divergence
[Objective] The utilization efficiency of land and water resources in the Huaihe River basin was evaluated to clarify the degree of coupling and coordination between the two and their spatial differentiation characterist...
Water Use Strategies of Typical Plants in a Tunnel Construction Area at Eastern Margin of Qinghai-Xizang Plateau
[Objective] The water use characteristics of plants and their responses to environmental changes in a tunnel construction area at the eastern margin of Qinghai-Xizang Plateau were studied in order to provide a reference...
Evapotranspiration Characteristics and Soil Moisture Conditions of Ginkgo Biloba in Urban Gardens
[Objective] The variation characteristics of 0—300 cm soil water content of urban garden green space in the Guanzhong area were studied to determine the variation characteristics of evapotranspiration and its components...