Comparative Assessment of Carbon Sequestration and Soil Properties in Rangeland and cropland (Case Study: Chatāl, Golestan Province)

Introduction: Population growth and increasing human needs have led to a rise in fossil fuel consumption and land-use changes, resulting in climate change and global warming. Carbon sequestration has gained significant importance as a management strategy for controlling atmospheric carbon levels. The objective of this study is to evaluate carbon sequestration rates and soil characteristics in rangeland and agricultural land uses in the Chatāl region of Golestan Province.
Material and methods: This study was conducted in the Chatal village watershed in Golestan Province, covering an area of 3000 hectares. Soil sampling was performed at 100 points at a depth of 0-30 cm. Parameters including bulk density, organic carbon, pH, electrical conductivity, soil texture, and aggregate stability were measured using standard methods. After determining and calculating all parameters, data normality was first examined using the Shapiro-Wilk test, and a t-test was used to compare the rangeland and agricultural land uses. Additionally, the correlation of the studied parameters was performed using the Pearson's correlation coefficient test using R software.
Results and discussion: The results indicated that the mean organic carbon content in rangeland land use (1.42%) was higher than in agricultural land use (0.79%). Additionally, the mean bulk density in agricultural land use (1.51 g/cm³) was lower than in rangeland (1.06 g/cm³). Soil aggregate stability in rangeland land use (8.51) was significantly higher than in agricultural land use (4.3). A significant positive correlation was observed between organic matter and carbon sequestration in both land uses, with correlation coefficients of 0.84 in rangeland and 0.77 in agricultural land use. Furthermore, electrical conductivity exhibited a negative impact on carbon sequestration in agricultural land use (correlation coefficient of -0.22).
Conclusion: The results of this study highlight the challenges in maintaining soil quality and carbon sequestration capacity in agricultural lands. Based on the comparison between rangeland and agricultural land uses, it is evident that rangeland land use plays a more significant role in carbon sequestration. This is due to the presence of more stable vegetation cover and better management of organic matter in rangelands. In agricultural land uses, common farming practices such as plowing and the use of chemical fertilizers can lead to a decrease in soil organic carbon content. In contrast, rangeland use, which typically includes more stable vegetation cover, can contribute to maintaining and increasing carbon sequestration. To enhance carbon sequestration capacity in both land use types, the following recommendations are proposed: Promote sustainable agricultural practices that help maintain soil structure and reduce soil compaction, Preserve and expand rangelands by preventing their conversion to agricultural lands, Provide necessary training to farmers about the importance of organic matter and methods to increase it in the soil, Conduct further research to identify best practices for increasing carbon storage in both land use types across different regions. These recommendations can contribute to effective management policies for mitigating the negative effects of climate change and emphasize the need for sustainable agricultural practices. Rangeland land use plays a greater role in carbon sequestration compared to agriculture. These findings emphasize that proper management of natural resources and preservation of vegetation cover can contribute to increasing carbon sequestration capacity. It is recommended to promote sustainable agricultural practices and prevent the conversion of rangelands to agricultural lands.