农田管理措施对滨海盐渍化土壤碳平衡的影响

为研究不同农田管理措施对滨海盐渍土壤碳平衡的影响,通过玉米-小麦轮作试验,研究农田土壤碳收支情况。试验共设6个处理:(1)常规对照(CK),(2)有机肥常量(OF),(3)氮肥增施(NF),(4)秸秆还田(S),(5)有机肥加秸秆(OF+S),(6)免耕(NT)。结果表明,秸秆还田和施用有机肥提高了土壤呼吸的强度,而NT处理的CO_2平均释放量最低,不同处理下土壤呼吸表现为OF+S处理S处理OM处理NF处理CKNT处理。各处理土壤有机碳量随着作物种植年份的增加而逐渐升高,其中OF与NT处理增加最多,而NF处理并没有显著提高土壤的有机碳量。在两季作物收获后,各处理的碳输入均高于碳输出,表现为碳净输入,呈现较强的碳汇特征。S处理和OF处理的碳净输入均显著高于CK,可有效减缓土壤CO_2排放,增加其有机碳的输入。

Effects of Different Farmland Managements on Carbon Balance in Coastal Saline Soils

To inquire into the effects of different management treatments on carbon balance of the coastal saline soils,field maize-wheat rotation experiments were conducted to study C balance in different management treatments.There were 6 treatments which were ① conventional tillage (CK);② application of organic fertilizer (OF);③application of nitrogen fertilizer (NF);④ application of straw (S);⑤ application of organic fertilizer and straw (OF + S);⑥ no tillage (NT).It turned out that treatments of S and OF increased the emission of soil CO2,and the average CO2 effiux of NT released a quantity to a minimum,the average rate of CO2 emission in different treatments showed as follows:OF + S＞S＞OM＞NF＞CK＞NT.After crops harvested,soil organic carbon content increased in each measure,the largest were OF and NT measures,NF did not significantly raise the content of soil organic carbon.After the experiment,carbon input were higher than carbon output in each measure,were all the net carbon input,it showed the strong characteristic of carbon sink.The C net inputs of S and OF measures were significantly higher than CK,these would effectively slow down the global climate change caused by the farmland soil CO2 emissions.