海南水田土壤有机质分布规律及碳固定潜力

Distribution of Soil Organic Matter and Carbon Potential Fixation in Paddy Soil in Hainan

研究海南水田土壤有机质分布规律及影响因素,并分析其碳固定的潜力。结果表明,海南水田土壤有机质含量平均为22.90 g/kg,相对于第二次土壤普查而言,水田土壤起着温室气体"源"的作用。土壤有机质的空间分布与按干湿状况划分的气候类型区关系密切,土壤有机质含量表现为湿润气候区>潮湿气候区>半湿润气候区>半干旱气候区。推行以增加农田土壤有机物质输入的管理方式和种植方式等都可以提高土壤的有机质含量,从而实现水田土壤温室气体"汇"的作用。

Change in soil organic matter is associated with the global climate change, and influences the soil quality and agricultural production. Soil organic matter was determined from samples collected from paddy soil in different climatic regions in Hainan, and the potential of carbon fixation also detected. The results showed that the paddy soil organic matter content was 13.3 g/kg in Hainan by average. Paddy soil acts as ＂source＂ of greenhouse gases based on the basic information of the second national soil survey. The spatial distribution of soil organic matter was closely related with the regions of climate types which are classified by wet and dry conditions. Of these climatic regions, the soil organic matter content was highest in the humid region, followed by in the wet region, in the semi-humid region, and in the semi-arid region, which is lowest. Soil management and cropping system which increase input of organic matter into soil can increase soil organic matter content so that the paddy soil acts as a ＂sink＂ of greenhouse gas.