长期不同施肥处理对水稻土有机碳分布变异及其矿化动态的影响  

EFFECTS OF LONG-TERM FERTILIZATION ON DISTRIBUTION AND MINERALIZATION OF ORGANIC CARBON IN PADDY SOIL

作　　者：马力[1,2] 杨林章[1] 慈恩[1,2] 程月琴[1,2] 王岩[1,2] 沈明星 殷士学[4] 

机构地区：[1]中国科学院南京土壤研究所,南京210008 [2]中国科学院研究生院,北京100049 [3]苏州太湖地区农业科学研究所,江苏苏州215155 [4]扬州大学资源与环境学院,江苏扬州225009

出　　处：《土壤学报》2009年第6期1050-1058,共9页Acta Pedologica Sinica

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)资助

摘　　要：基于持续26a的太湖地区水稻土长期定位试验，研究了长期施肥对水稻土剖面有机碳分布、有机碳密度和变异幅度、及有机碳矿化动态的影响。结果表明：（1）长期施肥使水稻土表层有机碳含量显著升高，施有机肥和秸秆还田较单施化肥更能促进表层有机碳累积。施化肥处理10～30cm土层有机碳含量相对稳定，施有机肥处理20～40cm土层有机碳含量相对稳定；（2）0～25cm和0～50cm土层，施有机肥处理的有机碳密度均高于施化肥处理，有机肥＋氮＋磷处理（MNP）和化肥氮＋磷＋钾处理（CNPK）的有机碳密度均为最高，秸秆＋化肥氮处理（CRN）高于有机肥＋秸秆＋氮处理（MRN）。各施肥处理0～25cm和25～50cm土层有机碳变异幅度均高于对照CO。施有机肥处理的有机碳密度变异幅度均高于施化肥处理。化肥氮＋磷处理（CNP）和有机肥＋氮＋磷＋钾处理（MNPK）有机碳密度的变异性最大；（3）各处理土壤有机碳矿化速率在培养第2～4天均达到最大，第3周后达到稳定，有机肥处理的最大矿化速率均高于化肥处理，各处理平均矿化速率为CO，55．36～75．46ml kg^-1 d^-1，稳定矿化速率为CO，10～20ml kg^-1d^-1。在8周培养期内，施有机肥处理的累积矿化量始终大于施化肥处理，有机肥＋秸秆＋氮处理（MRN）的累积矿化量最大，各施肥处理土壤的矿化强度和稳定矿化率仍保持稳定。Based on a 26-year-long fertilization experiment in paddy field, effects of fertilization on distribution, density and mineralization of organic carbon in soil profiles in paddy field were studied. Results show ： 1 ） Long-term fertilization significantly increased organic carbon content in the top soil, and Treatments MR （ application of organic manure plus return of crop straws） demonstrated a more contributive effect than Treatments CF （ application of chemical fertilization alone） on organic carbon accumulation in the top soil. Organic carbon content in the 10 - 30 cm soil layers of Treatments CF and in the 20 - 40 cm soil layers of Treatments OM （ organic manure） was relatively stable. 2） In the 0 - 25 cm and 0 - 50 cm soil layers, organic carbon density was found higher in Treatments OM than in Treatments CF, the highest in Treatments MNP and CNPK, and in Treatment CRN than in Treatment MRN. Compared with CK, Treatment CO （no fertilization） , all the other treatments varied more greatly in organic carbon in the 0 - 25 cm and 25 - 50 cm soil layers, Treatments OM did more than Treatments CF, and Treatments CNP and MNPK the most. 3） Organic carbon mineralization reached the peak in the first 2 - 4 days, and gradually leveled off in the 3 weeks that followed. The rate was higher in Treatments OM than in Treatments CF, with average mineralization rates varying in the range of CO2 55.36 - 75.46 ml kg^-1 d^-1 and stable mineralization rates in the range of CO2 10 - 20 ml kg^-1d^-1 In the eight weeks of incubation, Treatments OM were always higher than Treatments CF in cumulative mineralization and Treatment MRN was the highest. The total mineralization intensity and stable mineralization rate remained stable in all the treatments.

关 键 词：长期施肥 水稻土 有机碳 分布 变异 矿化 

分 类 号：S151.9[农业科学—土壤学] S153.6[农业科学—农业基础科学]