Guo An-Ning, Duan Gui-Lan, Zhao Zhong-Qiu, Tang Zhong, Wang Yang-Yang, Wang Bo-Xun
College of Land Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China.
Department of Soil Environment Science, Research Center for Eco-Environment Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Huan Jing Ke Xue. 2017 Aug 8;38(8):3483-3488. doi: 10.13227/j.hjkx.201701145.
Soil nitrification and denitrification are important steps in closing the nitrogen cycle. Understanding the effects of CaCO application on the physicochemical properties and nitrogen cycle in acid soil would provide some theoretical and technical information for stable and sustainable utilization of this agricultural soil. In this study, a field trial was conducted in Xiangtan city, Hunan province. In this field, the soil pH was 5.54, and CaCO was applied at four levels: 0, 2.25, 4.5, and 7.5 t·hm. After one season of rice cultivation, the soil was sampled to determine dissolved organic carbon (DOC), NH-N, and NO-N levels, and the potential nitrification rate (PNR) and denitrifying enzyme activity (DEA) were measured. The results showed that CaCO application improved the content of soil DOC (762.10-868.58 mg·kg) and PNR [0.59-0.82 μg·(g·h)]. However, excessive application of CaCO (7.5 t·hm) revealed an obvious inhibition on the activity of soil nitrification. Furthermore, the result of Pearson correlation analysis indicated that soil nitrification was positively correlated with soil DOC and negatively correlated with NH-N content, whereas denitrification had a significant positive correlation with NO-N content and soil DOC, but a negative correlation with water content.
土壤硝化作用和反硝化作用是氮循环闭合过程中的重要环节。了解施用碳酸钙对酸性土壤理化性质和氮循环的影响，可为该农业土壤的稳定可持续利用提供一些理论和技术信息。本研究在湖南省湘潭市进行了田间试验。该田间土壤pH值为5.54，碳酸钙按四个水平施用：0、2.25、4.5和7.5 t·hm 。经过一季水稻种植后，采集土壤样本测定溶解有机碳（DOC）、铵态氮（NH-N）和硝态氮（NO-N）水平，并测定潜在硝化速率（PNR）和反硝化酶活性（DEA）。结果表明，施用碳酸钙提高了土壤DOC含量（762.10 - 868.58 mg·kg）和PNR [0.59 - 0.82 μg·(g·h)]。然而，过量施用碳酸钙（7.5 t·hm ）对土壤硝化活性有明显抑制作用。此外，Pearson相关性分析结果表明，土壤硝化作用与土壤DOC呈正相关，与NH-N含量呈负相关，而反硝化作用与NO-N含量和土壤DOC呈显著正相关，但与土壤含水量呈负相关。
