The Research Of Crops Organic Carbon Sequestration And Economic Benefits Under Different Rotation Systems Of Guanzhong Plain In Shaanxi Province

Under the influence of global climate change, the carbon emissions had become a problem of common concern to the international community and the scientific community. As one part of the world’s most active carbon pool, farmland ecosystem carbon stocks has been affected by human activities. As the main grain producing areas of Shaanxi, the GuanZhong Plain plays an important role in food security. In order to provide theoretical basis and technical support for the efficient and reasonable system of energy conservation and emission reduction in Guanzhong area, we had this long-term experimental of wheat-fallow /wheat-soybean /wheat-maize /canola-maize rotations in Shannxi Province, this paper discussed the Soil organic carbon content, crops absorb carbon and the economic benefits. The result showed that:(1)Average soil organic carbon increasing amounts under different rotation treatments registered as wheat-fallow >wheat-soybean> wheat-maize > canola-maize. Soil organic carbon content was decreased with time of the wheat-fallow rotation modes. And the SOC of the wheat-maize rotation pattern had a slight increase. Other rotation patterns maintain a relatively stable level.(2)Crop carbon sequestration amounts under 4 different rotation modes compared that wheat-maize rotation had the highest crop carbon uptake with 119,886.31 kg C ? hm‐2, followed by canola-maize rotation with 115,551.78 kg C ? hm‐2 crop carbon sequestration amount, wheat-soybean and wheat-fallow rotations had the lowest carbon uptake with 64,996.12 kg C ? hm‐2 and 42,939.06 kg C ? hm‐2.(3)Economic benefits under 4 different rotation modes compared that wheat-maize rotation had the highest income with 27,534.61 yuan?hm‐2, followed by canola-maize and wheat-soybean rotation with 26,950.81 yuan?hm‐2 and 19,675.49 yuan?hm‐2 income, wheat-fallow rotations had the lowest income with 11,018.26 yuan?hm‐2. The proportion of outputs and inputs are as the same regular pattern as the income. Performance as wheat-maize(5.60) > canola-maize(5.29) > wheat-fallow(4.91) > wheat-soybean(4.73). The output value, net income, yield and yield ratio of different rotation modes are different. And the cost and production value of the four crop rotation mode is directly proportional to the cost, the higher the cost, the greater the output value. This shows that the capital investment in the production process has a positive impact on agricultural production. But from the pure income and output input ratio, winter wheat and summer maize rotation pattern had significantly better economic benefits, indicating that different regions of different rotation patterns between economic benefits is a big gap, rotation mode must do adjust measures to local conditions, to adapt to the local natural and social conditions.Rotation from the different treatment under four kinds of modes of view: from the point of view of the straw returning treatment: straw returning soil organic carbon content is higher, carbon absorption is also at a high level, but half the amount of straw to field level of economic benefits relatively high level, net income and the ratio of output to input was the highest, while the cost relatively low straw returning, so economic benefits and the full amount of straw returning to field correlation process is not high. This fully shows that the scientific straw incorporation is an effective way to improve the economic efficiency and yield ratio, and scientific, and can be fully utilized in the field of straw is the most important research. Therefore, how to find the optimal amount of straw returning under different rotation treatments is of great significance to agricultural production. And fertilization could significantly improve crop carbon absorption capacity, thereby reducing the content of soil organic carbon, and can obviously improve the yield and output value of four kinds of tillage mode, has good economic benefit, but because of the high cost of fertilization, fertilization amount still become limiting its net income and investment than a condition of production. Therefore, in view of the different rotation mode, we should do scientific and rational fertilization, not only improve the efficiency, but also reduce the cost.