Study On The Organic Carbon Migration And Sequestration Potential Of The Farmland Ecosystem In Semi-arid Regions Of Guyuan

As an important part of the terrestrial ecosystem,farmland ecosystems are characterized by short carbon sequestration cycles and large accumulations.They are the most active part of the global carbon pool,and slight changes in their content may cause large changes in CO2.In recent years,with the development and further implementation of global climate change and low-carbon organic agriculture,major changes have occurred in the nutrient status of farmland ecosystems,Therefore,quantitative analysis of organic carbon migration and carbon sequestration potential in farmland ecosystems has become a new focus.In order to further clarify the carbon sequestration potential of the farmland ecosystem in the semi-arid regions of Guyuan and its synergistic effect with increased yield,and to explore the organic carbon storage and migration patterns of the farmland ecosystem and their impact on crop production,with a view to providing data support for accurately assessing the nutrient utilization and enhancing the carbon sequestration potential of the farmland ecosystem,this study was conducted in Baiyang Township,Chengyang Township and Caomiao Township,Pengyang County,semi-arid regions of Guyuan for three consecutive years from 2017 to 2019,using the farmland ecosystem survey sampling method to sample the soil and plants during the maturity of plastic film maize and potato.The following findings were made.(1)The level of organic carbon content of the arable soil in the solid semi-regions is low,basically at level 5,which is a deficiency level.Soil organic carbon in the survey area's corn tillage layer ranged from 3.00 to 13.00 g/kg,with 14.29%at the extreme deficiency level,80.00%at the deficiency level,and 5.71%at the class ? criterion,which is below the moderate level.Potato soil organic carbon content is 4.00-13.00 g/kg,with 8.82%at the extreme deficiency level,88.24%at the deficiency level and 2.94%at the lower moderate level.This indicates that the organic carbon content of arable soil varies somewhat with land use and crop type,but the differences are not significant.The organic carbon content of potato tillage soils was relatively higher than that of ground corn,but the difference was not significant.(2)The increase in the organic carbon content of individual organs of plastic film maize and potato was positively correlated with the increase in the organic carbon content of tilled soil when the organic carbon content of tilled soil in the solid semi-regions was less than 13.00 g/kg.However,above this threshold,the rate of accumulation of organic carbon content in the plants gradually stabilized.Under the same conditions of soil organic carbon in the tillage layer,the organic carbon content of the various organs of the plastic film maize was expressed as:seeds>stems>leaves>roots,potato showed as follows:potato>stem>leaf.(3)The soil organic carbon content of the corn tillage layer ranged from 3.00-13.00 g/kg,and for every 1 g/kg increase in soil organic carbon content,the corn tillage layer increased yield by 0.27%-48.20%;the potato tillage layer increased yield by 2.53%-31.98%for every 1 g/kg increase in soil organic carbon content in the range of 4.00-13.00 g/kg.The increase in crop yields tends to plateau as the soil organic carbon content increases.For each 50.00 g/kg increase in organic carbon content,the actual yield increased by 5.97-211.26%at an average organic carbon content of 250.00-500.00 g/kg for plastic film maize(roots,stems,leaves).The average organic carbon content of potato(stem and leaf)ranged from 250-400 g/kg,and for every 50.00g/kg increase in organic carbon content,there was a decrease of 0.28-1.56 pieces per plant and an increase of 19.89-28.20 g per piece of potato weight.It was shown that after the average organic carbon of potato plants(stems,leaves)exceeded 450.00 g/kg,more nutrients flowed to the plants,which was detrimental to the accumulation of crop yield.The increase in kernel organic carbon content of maize seeds between 350.00-650.00 g/kg showed a positive positive effect on maize yield.When the organic carbon content of potatoes ranged from 250.00-400.00 g/kg,the number of potatoes per block continued to decline,the weight per block fluctuated higher and the actual yield showed a fluctuating downward trend.Overall,organic carbon as a basis for sustainable agricultural development has a positive positive effect on crop yields within a certain threshold,beyond which yield formation and accumulation are not favoured(4)The organic carbon densities of soil organic carbon in solid semi-arid regions were 1.81 kg/m2 and 1.79 kg/m2,respectively.The organic carbon stock of soil organic carbon in tillage layer was about 1.63 × 106 g for tillage layer maize and 1.29×106 g for tillage layer potato.From the interannual relationship,the organic carbon density of soil organic carbon in tillage layer increased continuously from 2017 to 2019,and the organic carbon stock of soil organic carbon in tillage layer increased by 0.17 × 106 g at a growth rate of 5.82%,with an average annual increase of 2.91%.The average of the vegetation carbon stocks of field crops is 50.44×104t,and the vegetation carbon stocks of membrane corn and potato crops are 25.61×104t and 24.83×104t,respectively.The vegetation carbon density of membrane corn and potato crops is 3.03 t/hm2 and 2.98 t/hm2,respectively.Therefore,the carbon sequestration potential of farmland ecosystems in semi-arid regions of China is huge.The above conclusions are derived from the 2017-2019 experimental study on farmland in the semi-regions of Guyuan,and long-term positioning studies on a wider regional and longer time scale are needed to systematically study the organic carbon transport and sequestration potential of farmland ecosystems in the semi-regions,and to further improve the accuracy of the findings.Studies have shown that increasing the organic carbon content of tillage soils can significantly increase the level of crop production and the carbon stock of farmland ecosystems in the semi-regions of Guyuan.It can be seen that maintaining a high level of soil organic carbon has a dual effect on soil fertilization and carbon sequestration in farm ecosystems,and is an important guarantee for the development of sustainable and environmentally friendly agriculture.