基于长期定位试验的水稻土氮素剖面分布及养分供应特性研究  

Profile Distribution of Nitrogen and Nutrient Supply Characteristics of Paddy Soil Based on Long-Term Fertilization Experiment

作　　者：马力[1] 杨林章[1] 慈恩[1] 王岩[1] 程月琴[1] 沈明星 殷士学[3] 

机构地区：[1]中国科学院南京土壤研究所 [2]苏州太湖地区农业科学研究所,江苏苏州215155 [3]扬州大学环境科学与工程学院,江苏扬州225009

出　　处：《水土保持学报》2008年第4期116-121,127,共7页Journal of Soil and Water Conservation

基　　金：国家重点基础研究发展规划项目(2005CB121108);中国科学院知识创新工程重要方向项目(KZCX2-YW-407)

摘　　要：基于已持续26年的水稻土长期定位试验,研究了长期施肥对水稻土剖面氮素迁移分布和C/N的影响,不同施肥方式下土壤氮素矿化曲线和硝化强度变化,以及累积矿化量与有效积温的关系,结果表明:(1)长期施肥使土壤表层氮素累积量明显增加,土壤剖面含氮量分布曲线呈"S"形。0-20 cm土层,施有机肥处理的含氮量普遍高于施化肥处理,20-30 cm土层,化肥氮+磷处理(CNP)、化肥氮+磷+钾处理(CNPK)、秸秆+化肥氮处理(CRN)和不施肥对照C0的含氮量高于有机肥+氮+磷处理(MNP)、有机肥+氮+磷+钾处理(MNPK)、秸秆+有机肥+氮处理(MRN)和仅施有机肥处理(M0),而40-50 cm土层含氮量差异较小;(2)土壤矿化曲线在前期差异明显,7 d后的矿化量普遍达最大,28 d后趋于稳定,施有机肥处理7 d后的矿化量明显高于施化肥处理。土壤累积矿化量与有效积温的关系符合有效积温方程式,矿化常数K和n值反映了施有机肥土壤氮素的矿化潜力较大,而施化肥土壤的矿化过程达稳定状态需更长时间;(3)长期施肥使土壤的硝化强度明显提高,施有机肥处理普遍高于施化肥处理。MNPK最高,比C0提高了6.44倍,秸秆还田处理CRN高于CNP和CNPK;(4)施有机肥或秸秆使表层土C/N值有降低趋势。0-10 cm表层土壤的C/N值,CNPK>MNPK,C0>M0,而秸秆还田处理MRN的C/N值最低。20-50cm土层,施有机肥处理的C/N普遍高于化肥处理,施化肥土壤下层的有机质分解程度较高。Based on long-term fertilization experiment for 26 years in paddy field, the effects of long-term fertilization on profile distribution of soil nitrogen and C/N, Soil nitrogen mineralization characteristics, nitrification rate and relationship between cumulative mineralization and effective accumulated temperature were studied, the result showed： （1） Topsoil nitrogen accumulation significantly increased, profile distribution curves of soil nitrogen were in ＇S＇ shape. Total nitrogen contents of 0--20 cm soil layer of organic manure treatments were higher than that of chemical fertilizer treatments. In 20--30 cm soil layer, nitrogen content of CNP,CNPK and CO was higher than MNP, MNPK, MRN and M0. There are little differences of nitrogen contents in 40--50 cm soil layer; （2） Soil nitrogen mineralization curves were significantly different in prophase. Mineralization of different treatments general reached maximum after 7 d and tended to be stable after 28 d. Mineralization of organic manure treatments was higher than that of chemical fertilizer treatments after 7 d. Cumulative mineralization and effective accumulated temperature were in good accord with effective accumulated temperature model. Mineralization constant K and n reflected that organic manure treatments may had more mineralization potentials and mineralization processes of chemical fertilizer treatments may require more time to reach stable state ; （3） Nitrification rates of all treatments were increased, organic manure treatments were higher than chemical fertilizer treatments, CRN was higher than CNP and CNPK. Nitrification rate of MNPK was the maximum and increased 6.44 times compared with C0; （4） Organic manure and straw applications may result in C/N of topsoil decreased. For C/N of 0--10 cm soil layer,CNPK〉MNPK,C0〉 M0,MRN was the lowest. For C/N of 20--50 cm soil layer,Organic manure treatments were general higher than chemical fertilizer treatments,and subsoil of chemical fertilizer treatments had higher degree of SOM de

关 键 词：长期定位试验 水稻土 氮素 分布 养分供应 

分 类 号：S151.9[农业科学—土壤学] S157.4[农业科学—农业基础科学]