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在宏观层面上利用中国1990—2011年的机械化秸秆还田机数量,推算出1990—2011年秸秆还田面积,探讨了20多年来中国秸秆还田情况,并研究了第一次土壤普查、第二次土壤普查和测土配方施肥近60年中国土壤有机碳的变化规律,分析了秸秆还田面积与土壤有机碳含量的关系。结果表明:1990—2011年,中国秸秆还田面积整体上呈上升的趋势,2011年机械化秸秆还田面积是1990年的2.92倍,但与粮食播种面积相比,我国的秸秆还田面积所占的比例很低,2011年机械化秸秆还田面积占粮食作物播种面积的比例(全国均值)只有16.89%。我国31个省(自治区、直辖市)中,有近50%的省份土壤有机碳含量呈现增加的趋势。在区域范围内表现为华北、华东、华中、西北地区土壤有机碳含量增长明显,而西南、华南和东北地区土壤有机碳呈现降低的趋势,尤其是东北地区降幅明显。
At the macro level, the amount of straw returned to farmland in 1990-2011 was estimated by using the number of mechanized straw returning machines in China from 1990 to 2011. The situation of returning straw to soil in China over the past 20 years was also discussed. The first soil survey, Secondary soil census and soil testing and fertilizer application in recent 60 years of China’s soil organic carbon changes in the law to analyze the relationship between straw returning area and soil organic carbon content. The results showed that from 1990 to 2011, the area of straw returning to China showed an overall upward trend. In 2011, the area of straw returned to mechanization was 2.92 times that of 1990, but compared with the sown area of grain, the area of straw returning to the country accounted for The proportion of mechanized straw-returning area to the sown area of food crops in 2011 (the national average) is only 16.89%. Of the 31 provinces (autonomous regions and municipalities directly under the Central Government), nearly 50% of the provinces in China show an increasing trend of soil organic carbon. In the region, soil organic C content increased obviously in North China, East China, Central China and Northwest China, while the soil organic carbon in Southwest, South China and Northeast China showed a decreasing trend, especially in Northeast China.