Total Organic Carbon Density Research Articles

Spatiotemporal Simulation and Prediction of Soil Organic Carbon Density in Gannan Grassland Under Future Climate Scenarios

To study the temporal and spatial distribution characteristics of soil organic carbon density in grassland and explore the relationship between organic carbon density and influencing factors is of great significance to the management and maintenance of grassland ecosystems in Gannan Autonomous Prefecture, which is conducive to realizing the goal of "double carbon," promoting carbon sink, and mitigating climate change. Taking Gannan Tibetan Autonomous Prefecture of Gansu Province as the research object, based on data from two CMIP6 future climate scenarios (SSP126 and SSP585), the CENTURY model was used to simulate and predict the temporal and spatial changes in soil organic carbon density in grassland of Gannan during 2023-2100. The main conclusions were as follows:① From 2023 to 2100, total organic carbon density, slow organic carbon density, and inert organic carbon density all showed a downward trend, whereas active organic carbon density fluctuated first and then increased. Meanwhile, the total organic carbon density, active organic carbon density, slow organic carbon density, and inert organic carbon density under the SSP585 scenario were higher than those under the SSP126 scenario. ② Mann-Kendall mutation analysis showed that the abrupt change in the difference of soil total organic carbon density (Δsomtc) occurred in 2030. The abrupt change in the difference of soil active carbon density (Δsom1c) occurred in 2027. ③ During the study period, the average soil organic carbon density of Gannan grassland was 7 505.69 g·m-2 under the SSP126 scenario and 7 551.87 g·m-2 under the SSP585 scenario. Gannan grassland soil organic carbon density was higher in the west and lower in the east, and the coefficient of variation was relatively stable. ④ The results of partial correlation analysis showed that precipitation was positively correlated with soil organic carbon density, whereas temperature was significantly negatively correlated with soil organic carbon density under future climate scenarios. ⑤ The results of the Theil-Sen Median trend analysis and Mann-Kendall test showed that under the two climate scenarios, the soil organic carbon density in Gannan showed an overall downward trend, in which Luqu County showed the fastest downward trend and Dibe County showed the slowest.

Spatial Pattern of Soil Carbon Density in Cultivated Land of Different Domains of Madhya Pradesh

Present study was conducted in the Department of Soil Science JNKVV, Jabalpur during 2018-2020. GPS based 531 soil samples were collected from each domain viz., Bhopal, Jabalpur, Vidisha and Hoshangabad of 10.1 Agro ecological sub region (AESR). The samples analyzed for soil organic carbon (SOC) and calcium carbonate (CaCO3) then soil organic carbon density (SOCD), total organic carbon density (TOCD), soil inorganic carbon density (SICD) and total carbon density (TCD) in Mg C ha-1 were calculated. The results of SOCD, TOCD, SICD and TCD ranged from 4.73 to 25.12, 9.22 to 48.98, 1.00 to 21.29 and 11.08 to 68.80 Mg C ha-1 with mean value of 12.19, 23.78, 7.58 and 31.36 Mg C ha-1 in AESR 10.1 and Coefficient of variation (CV) 37.58, 37.58, 50.88 and 31.24 %. The overall trend in SOCD was Bhopal > Vidisha > Jabalpur > Hoshanagabad and SICD was Vidisha > Hoshanagabad > Jabalpur >Bhopal while TCD was in trend of Bhopal > Vidisha > Hoshangabad> Jabalpur.
 Geo-statistical indicated that Ordinary Kriging used and all variogram were in isotropic form. In Bhopal domain, Gaussian model best fitted for of SOCD, TOCD, and TCD but spherical model for SICD. In Jabalpur domain, exponential domain best fitted for TCD and TOCD but for SICD, spherical model and for SOCD, Gaussian model is best fitted. In Vidisha domain, exponential model best fitted for all. In Hoshangabad domain, exponential model is best fitted for SOCD and TOCD and Gaussian and J-Bessel model best fitted for TCD and SIC, respectively. The nugget/ sill (N/S) ratio was <25% which exhibit strong SD only for SICD in Bhopal domain. The N/S ratio was found to be >25% but <75% which showed moderate SD, for SOCD, TOCD and TC, TOCD, SICD and TCD; SOCD, TOCD, SICD and TCD and SOCD, TOCD, SICD and TCD in Bhopal, Jabalpur, Vidisha and Hoshangabad domain, respectively. The correlation range (m) for SOCD, TOCD, SICD and TCD are 5448.413, 4809.535, 360.522, and 5113.050; 7201.044, 6601.044, 611.651, and 8438.711; 5734.559, 7334.398, 1323.773, and 7881.289 and 5418.684, 5433.206, 8887.656, and 1836.274 in Bhopal, Jabalpur, Vidisha and Hoshangabad domain, respectively. The carbon density was found in order of Jabalpur> Hoshangabad >Vidisha > Bhopal.