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在野外取样的基础上,研究中国不同典型地带性土壤各形态氮素分布特征及其影响因素.结果表明:垂直地带性土壤中0.5 mol·L~(-1)K_2SO_4提取的提取态总氮、提取态有机氮、吸附氨基酸随取样点海拔的增加而显著增加,且提取态总氮、提取态有机氮和吸附氨基酸平均值都大于水平地带性土壤;水平地带性土壤各形态氮含量随土壤类型的不同而差异显著.土壤吸附氨基酸含量是游离氨基酸的5倍,占提取态有机氮百分比为21.1%,表明吸附氨基酸可能作为土壤有机氮库的一种重要存在形态.相关分析结果表明,垂直地带性土壤中提取态总氮、提取态有机氮、铵态氮、氨基酸态氮均与有机质、全氮呈显著正相关(r=0.57~0.93,P<0.05),但与pH、硝态氮呈显著负相关(r=-0.37~-0.91,P<0.05);水平地带性土壤pH与提取态总氮、硝态氮、有机质、全氮、碱解氮及盐基离子(K~+、Ca~(2+)、Mg~(2+))呈显著正相关(r=0.36~0.85,P<0.05),与铵态氮、氨基酸态氮呈显著负相关(r=-0.39~-0.81,P<0.05).
Based on the field sampling, the characteristics and influencing factors of various forms of nitrogen distribution in different typical zonal soils of China were studied. The results showed that the total nitrogen extracted from 0.5 mol·L -1 K 2 SO 4 in vertical zonal soils, Extracted organic nitrogen, amino acid adsorption increased significantly with the elevation of the sampling point, and the total nitrogen extracted, extraction of organic nitrogen and adsorbed amino acids are greater than the average level of zonal soil; horizontal zonal soil nitrogen content with soil type The content of amino acids in soil is five times of that of free amino acids, accounting for 21.1% of organic nitrogen in extracted state, which indicates that the adsorption of amino acids may be an important existing form of soil organic nitrogen pool.The correlation analysis shows that in the vertical zone Soil organic nitrogen, ammonium nitrogen and amino acid nitrogen in extracted soil were positively correlated with organic matter and total nitrogen (r = 0.57 ~ 0.93, P <0.05), but with pH and nitrate nitrogen (R = -0.37 ~ -0.91, P <0.05). Soil pH and total nitrogen, total nitrogen, total nitrogen, available nitrogen and salt ions (K ~ +, Ca ~ (2 +), Mg ~ (2+)) was significant Correlation (r = 0.36 ~ 0.85, P <0.05), and was ammonium, amino acid nitrogen significant negative correlation (r = -0.39 ~ -0.81, P <0.05).