黑土有机氮组分在甜菜生长季矿化特征的研究

Mineralization Characteristic of Organic Nitrogen in Black Soil Period of Sugar Beet Growth

采用田间、盆栽试验、室内好气培养和Bremner酸解法测定有机氮组分相结合的研究方法，探讨了甜菜生长季黑土有机氮组分变化及其矿化特征。结果表明，酸解总氮是黑土有机氮的主要组成部分，占土壤总氮的66％～97％，而非酸解态氮仅占较小的比例。施肥处理（N120／P120／K120）增加了从叶丛生长期（6月）到收获期（9月）土壤有机氮组分中酸解总氮和氨基酸态氮含量。在甜菜幼苗期（5月），黑土酸解有机氮各组分比例由大到小的次序为：氨态氮〉未知态氮〉氨基酸态氮〉氨基糖态氮。随着甜菜的生长，氨基酸态氮含量增幅最为明显，在叶丛生长期（6月）和糖分积累期（7月）达到高峰，施肥处理增幅均高于其他处理（N0／P120／K120，CK1，CK2），氨态氮无明显变化，未知态氮随着甜菜的生长，所占比例明显下降，因此到叶丛快速生长期后，各个处理酸解总氮的4种组分占全氮比例依次为：氨基酸态氮〉氨态氮〉未知态氮〉氨基糖态氮。经好气培养91d后，施肥处理明显增加土壤的累积矿化量，供氮潜力（N0）和供氮强度（k），土壤矿化势与氨基酸态氮呈显著正相关，相关系数为0．951（p〈0．05），与非酸解态氮和氨基糖态氮呈负相关，表明氨基酸态氮是土壤可矿化态氮的主要贡献者。

By field and pot experiment, the dynamic change of organic nitrogen components and mineralization characteristics in black soil period sugar beet growth were measured by Bremner acid hydrolysis and aerobic culture. Results show that the total hydrolysable nitrogen is the main component of organic nitrogen of black soil composition, the percentage of soil total nitrogen was 66〉97〉, rather than the non-hydrolysable ni- trogen only accounts for a smaller proportion. The total hydrolysable nitrogen and amino acid nitrogen con- tent of fertilizer treatments（N120/P120/K120） in soil increased period leaf and cluster growth （June） to harvest （September） of sugar beet. On sugar beet seedlings stage （May）, organic nitrogen components of black soil respectively proportion order for ammonia nitrogen〉unknown nitrogen〉amino acid nitrogen〉amino sugar nitrogen, along with the growth of the sugar beet, amino acid nitrogen content increased most obviously, reach a peak cluster in leaves（June） and sugar accumulation（July） for a long time period, increase fertiliza- tion treatment were higher than other treatment（N0/P120/K120, CK1,CK2）, there was no significant altera- tion of the ammonia nitrogen, nitrogen unknown as the growth of the sugar beet, significantly lower propor- tion of, so the cluster after rapid growth period, the individual processing of total hydrolysable nitrogen ratio is characterized by four components of amino acid nitrogen〉ammonium nitrogen〉unknown nitrogen〉amino sugar nitrogen. After aerobic culture 91 d, fertilization treatment can significantly increase the amount of cu- mulative mineralized soil, for potential mineralizable nitrogen （No） and nitrogen supply intensity （k）, soil potential mineralization and amino acid nitrogen were significantly positive correlation, the correlation coeffi- cient was 0. 951（p〈0.05）, and non-hydrolysable nitrogen and amino sugar nitrogen showed a negative correlation, that is soil nitrogen amino acid and the main contributor to the mineralized nitrogen.