施加碳酸钙对酸性土壤微生物氮循环的影响

发布时间：2018-12-10 10:36

【摘要】：土壤硝化作用和反硝化作用是闭合氮循环的重要步骤,阐明在酸性土壤施用碳酸钙(CaCO_3)对土壤理化性质及土壤氮循环的影响,可为农田质量稳定和可持续利用提供理论依据和技术支持.以湖南省湘潭市酸性土壤为研究对象,设计了4个CaCO_3施加量,分别为0、2.25、4.5和7.5 t·hm~(-2),在种植一季水稻后,分析了不同CaCO_3施加量对土壤理化性质、硝化作用和反硝化作用的影响.结果表明CaCO_3的施加,显著提高了土壤溶解有机碳(dissolved organic carbon,DOC)762.10~868.58mg·kg~(-1),促进土壤硝化作用[0.59~0.82μg·(g·h)~(-1),以NO_2~--N/土计],但当CaCO_3施加量达7.5 t·hm~(-2)时对硝化作用产生抑制,土壤反硝化作用对CaCO_3的响应较为复杂.Pearson相关分析结果表明,土壤硝化作用与土壤DOC显著正相关,和NH_4~+-N含量显著负相关,反硝化作用与NO_3~--N含量、土壤DOC显著正相关,和含水量显著负相关.
[Abstract]:Soil nitrification and denitrification are important steps to close the nitrogen cycle. The effects of calcium carbonate (CaCO_3) application on soil physical and chemical properties and soil nitrogen cycling in acidic soils were clarified. It can provide theoretical basis and technical support for farmland quality stability and sustainable utilization. The acid soil of Xiangtan City, Hunan Province was used as the research object. Four CaCO_3 applied amounts were designed, which were 0 ~ 2.25 hm~ (-2) and 7.5t hm~ (-2), respectively. The physicochemical properties of the soils were analyzed after the cultivation of one-cropping rice. Effects of nitrification and denitrification. The results showed that the application of CaCO_3 significantly increased the 762.10~868.58mg kg~ (-1) of dissolved organic carbon (dissolved organic carbon,DOC) in soil and promoted soil nitrification [0.59 ~ 0.82 渭 g (g h) ~ (-1)]. But when the amount of CaCO_3 was 7.5t hm~ (-2), the response of soil denitrification to CaCO_3 was more complex. The results of Pearson correlation analysis showed that the soil denitrification was more sensitive to CaCO_3. Soil nitrification was positively correlated with soil DOC, negatively correlated with NH_4~ N content, and negatively correlated with NO_3~--N content, soil DOC content and soil water content.
【作者单位】：中国地质大学(北京)土地科学技术学院;中国科学院生态环境研究中心土壤环境研究室;南京农业大学资源与环境科学学院;首都师范大学资源环境与旅游学院;
【基金】：公益性行业(农业)科研专项(201403015) 浙江省自然科学基金项目(LY15D010001) 浙江省嘉兴市科技计划项目(2014AZ21001)
【分类号】：S154.3

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