植物营养与肥料学报Issue(6)：1421-1430,10.DOI:10.11674/zwyf.2014.0612
外源化肥氮素在土壤有机氮库中的转化及关系
Transformation of external chemical nitrogen in soil organic nitrogen fractions and their relationship
摘要
Abstract
Objectives]In this study,the transformation and re1ationshiP of externa1 chemica1 N in soi1 organic nitrogen( SON)fractions were determined during one growing season of rice in order to Provide a theoretica1 basis for reasonab1e ferti1izer aPP1ication and the effective adjustment to N ferti1izer.[Methods]A Pot exPeriment was carried out on a subtroPica1 Paddy soi1 in Jiangxi Province,and a tota1 N 180. 0 kg/ha(15 N 1abe1ed urea,atom 10. 3%)was aPP1ied to a rice croP during one growing season under the conventiona1 farmer Practices. Distribution and dynamics of the chemica1 N ferti1izer in different SON fractions( i. e. ,amino acid N,amino sugar N, hydro1ysab1e ammonium N,hydro1yzab1e unknown N and acid inso1ub1e N)were measured. Path ana1ysis was used to eva1uate the transformation Process between SON derived from the ferti1izer in soi1-P1ant system.[Results]1 ) The accumu1ation of ferti1izer-derived N in different SON fractions was season-sPecific. The recovery contents of the ferti1izer-derived N in soi1 amino acid N and amino sugar N at the jointing stage are significant1y higher than those at the ti11ering stage( P<0. 05 ). The enrichments of 15 N are significant1y dec1ined from the jointing stage to fi11ing stage( P<0. 05 ). The dynamics of enrichment of 15 N in soi1 amino acid N and amino sugar N during the growing season can be fitted as a Gauss equation,the maximum contents are 26. 5 and 8. 4 mg/kg,resPective1y,which are found between the ti11ering stage and jointing stage. The enrichment of 15 N in hydro1ysab1e ammonium N is dec1ined gradua11y from the ti11ering stage to harvest stage,and the dynamics of the enrichment of 15 N in soi1 hydro1ysab1e ammonium N cou1d be exPressed as an exPonentia1 dec1ine equation. The enrichment of 15 N in hydro1yzab1e unknown N is gradua11y in a dynamica1 equi1ibrium from the ti11ering stage to harvest stage,and the dynamics of the enrichment of 15 N in soi1 hydro1ysab1e unknown N can be fitted as an exPonentia1 equation. The enrichment of 15 N in acid inso1ub1e N can be fitted as a symmetry equation,and the minimum of the enrichment of 15 N is 7. 9 mg/kg, which is found between the jointing stage and fi11ing stage. 2 )At the ti11ering stage and jointing stage of rice, Preferentia1 enrichment of 15 N is found in soi1 hydro1ysab1e ammonium N and amino acid N,accounting for 21. 5%and 14. 8% of the tota1 N of the chemica1 N ferti1izer,resPective1y. The accumu1ation of residua1 ferti1izer-derived N in acid inso1ub1e N is higher at the fi11ing and harvest stages,accounting for 8. 7% and 12. 7% of the tota1 N of the chemica1 N ferti1izer,resPective1y. 3 )The Path ana1ysis indicates that the hydro1ysab1e ammonium N is a temPorary Poo1 for raPid chemica1 N ferti1izer retention and is aPt to re1ease N for croP uPtake simu1taneous1y. In contrast,the amino acid N cou1d serve as a transitiona1 Poo1 of avai1ab1e N in soi1 system through transferring into hydro1ysab1e ammonium N and amino sugar N. 4)The ferti1izer-derived N in hydro1ysab1e ammonium N and amino acid N are c1ose1y re1ated to ferti1izer-derived N in croP uPtake.[Conclusions]In a P1ant-soi1 system,the ferti1izer N cyc1ing during a growing season is c1ose1y re1ated to temPora1 Patterns of ferti1izer N transformation into different SON fractions. The ferti1izer-derived N can be derived into three Poo1s with different avai1abi1ities. The hydro1ysab1e ammonium N fraction can serve as a temPorary Poo1 containing readi1y avai1ab1e N to be re1eased fast,whi1e the amino acid N can be considered as a transitiona1 Poo1 for the transformation of the hydro1ysab1e ammonium N and amino sugar N,and the acid inso1ub1e N is tight1y associated with ferti1izer N stabi1ization. ImPortant1y,there is an interim shift among the three substantia1 N Poo1s to maintain soi1 N cyc1ing and suPP1y in a soi1-P1ant system.关键词
15 N示踪/土壤有机氮/转化及关系Key words
15 N 1abe1ed/soi1 organic N fraction/transformation and re1ationshiP分类
农业科技引用本文复制引用
姜慧敏,王峰源,李树山,张建峰,杨俊诚,李玲玲,张水勤,郭俊娒,刘恋,谢义琴..外源化肥氮素在土壤有机氮库中的转化及关系[J].植物营养与肥料学报,2014,(6):1421-1430,10.基金项目
国家重点基础研究发展计划（973项目）（2013CB127406）；中央级公益性科研院所专项资金项目（IARRP-2014-8）；国家自然科学基金项目（21107139）；国家国际科技合作专项（S2015ZR1163）；农业部公益性行业科研专项（201103007）资助。 （）
