长期施肥对华北典型潮土N分配和N2O排放的影响

利用长期定位肥料试验研究化学肥料N、有机肥料N以及化学肥料N和有机肥料N混合施用对N分配和N2O排放影响。处理包括化学肥料N、P、K的不同组合NPK、NP、NK、PK、全部施用有机肥料N（OM）、一半化学肥料N＋一半有机肥料N（1／2OM）及不施肥（CK）7个处理。结果表明，等N条件下，处理间N2O排放的差异不显著，N2O排放主要发生在玉米生长期。均衡提供N、P和K显著提高土壤N储量，有机肥料N的效果显著高于化学N肥。施肥也影响N的利用效率和N在作物中的分配。均衡的养分供应有利于N在子粒中积累，而养分缺乏的处理，秸秆中N含量相对较高。进入环境的N量以NK最多，1／20M最少。总体而言，施P肥和有机肥可减少N2O的间接排放，提高土壤N素肥力并能获得较高的产量。

Effects of long-term fertilization on N distribution and N2O emission in fluvo-aquci soil in North China

N distribution in soil-plant system and N2O emissions from soil was investigated in a long-term fertilization field experiment in fluvo-aquci soil in North China. In this experiment, there were 7 treatments: organic manure N (OM), half organic manure N and half fertilizer N (1/2OM), fertilizer NPK (NPK), fertilizer NP (NP), fertilizer NK (NK), fertilizer PK (PK) and control (CK). The results showed that N2O emissions from soil during maize growth was higher than during wheat growth, but the differences of soil N2O emissions among the treatments were insignificant in same N fertilization. Balanced fertilization of N, P and K increased soil N storage, while the efficiency of organic manure N application was higher than chemical N application. N utilization efficiency and distribution in plants was also significantly influenced by the fertilization. Balanced nutrient application was beneficial to N accumulation in seeds, but nutrient deficiency was inclined to accumulate N in straws. The N lost from soil was highest in NK and least in 1/2OM treatment. In summary, application of P fertilizer and organic manure not only reduce the indirect N2O emission from soil, but also increase soil fertility and crop yields.