外源氮输入对黄河口碱蓬湿地土壤碳氮含量动态的影响

发布时间：2018-06-22 11:06

本文选题：氮输入 + 碳氮　；参考：《水土保持学报》2017年06期

【摘要】：2014年4—11月,选择黄河入海口北部滨岸高潮滩的碱蓬湿地为研究对象,基于野外原位氮输入模拟试验,研究了不同氮输入梯度下(N0,无氮输入;N1,低氮输入;N2,中氮输入;N3,高氮输入)湿地土壤碳氮含量动态特征及其差异。结果表明,不同氮输入处理下土壤的SOC、TN、NH_4~+—N和NO_3~-—N含量整体上均随着土层深度的增加而逐渐降低,各土层的SOC和NO_3~-—N含量在N2处理最高,而TN和NH_4~+—N含量在N3处理最高。尽管不同氮输入处理并未改变湿地土壤中TN和NH_4~+—N含量的动态变化模式,但随氮负荷增强二者含量均呈增加趋势。不同的氮输入处理明显改变了土壤中SOC和NO_3~-—N的动态变化模式,适量氮输入(N1和N2)明显提高了土壤中的NO_3~-—N含量,过量氮输入(N3)则不利于NO_3~-—N的累积;不同氮输入处理下(特别是N2和N3处理)湿地表层土壤(0—20cm)的SOC含量在7月中旬后远大于N0处理(P0.05),说明持续的氮输入可能不利于表层土壤中SOC的转化。研究发现,当未来黄河口湿地氮养分达到N1和N2水平时将有利于土壤氮矿化,而这将使得土壤氮养分的供给更为充足;但氮负荷持续增强可能使土壤表层的SOC转化受到抑制,而这将有助于提升土壤的储碳功能。
[Abstract]:From April to November 2014, the Suaeda salsa wetland on the northern shore of the Yellow River estuary was selected as the research object, and the simulation experiment of in-situ nitrogen input in the field was carried out. The dynamic characteristics and differences of soil carbon and nitrogen contents in wetland soils were studied under different nitrogen input gradient (N0, no nitrogen input N 1, low nitrogen input N 2, medium nitrogen input N 3, high nitrogen input). The results showed that the contents of soil SOCN TNS NH4- N and NO3- +-N decreased gradually with the increase of soil depth under different nitrogen input treatments. The SOC and NO3- -N contents of soil layers were the highest in N2 treatment, while TN and NH4- N contents were highest in N3 treatment. Although different nitrogen input treatments did not change the dynamic change pattern of TN and NH4- N contents in wetland soil, they both showed an increasing trend with the increase of nitrogen load. Different nitrogen input treatments changed SOC and NO3 N dynamic change patterns in soil obviously. Proper nitrogen input (N1 and N2) significantly increased NO3 N content in soil, while excessive nitrogen input (N3) was not conducive to NO3 N accumulation. The SOC content of surface soil (0-20cm) of wetland under different nitrogen input treatments (especially N2 and N3 treatment) was much higher than that of N0 treatment after mid-July (P0.05), which indicated that the continuous nitrogen input might not be conducive to the transformation of SOC in surface soil. It was found that nitrogen mineralization would be beneficial to soil nitrogen mineralization when N _ 1 and N _ 2 levels were reached in the wetland of the Yellow River Estuary in the future, which would make the soil nitrogen nutrient supply more adequate, but the continuous increase of nitrogen load might inhibit the SOC transformation of soil surface layer. This will help improve the carbon storage function of the soil.
【作者单位】：福建师范大学地理研究所湿润亚热带生态地理过程教育部重点实验室;山东省黄河三角洲生态环境重点实验室(滨州学院);路易斯安那州立大学植物、环境与土壤科学系;鲁东大学地理与规划学院;成都信息工程学院资源环境学院;
【分类号】：S153.6

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