黄河上游灌区稻田氨挥发损失研究

摘要

采用密闭气室间歇式抽气法研究了黄河上游灌区不同施肥处理下稻田氨挥发损失特征。结果表明，在水稻全生育期不同施肥处理下稻田氨挥发量为N27．6～94．1kg／hm^2，肥料氮损失率为16．4％～22．2％；不同施肥阶段氨挥发损失持续时间为10d左右，氨挥发最大峰值均发生在施肥后2～3d；分蘖肥后氨挥发损失量最大，损失量占全生育期损失总量的27．1％～37．0％。温度、光照、pH值是黄河上游灌区氨挥发的主要影响因素，稻田田面水铵浓度与氨挥发呈显著线性正相关。稻田氨挥发损失量随氮肥施用量的增加而增加，与习惯施肥（N300）相比，减氮20％（N240）及有机肥和化肥配合施用（N240-1/20M）均能有效减少稻田氨挥发损失，且这两个处理的水稻产量最高，是生态效益和经济效益双赢的最佳模式。%The batch-type airflow enclosure method was adopted to measure the ammonia volatilization （AV） from paddy field under different fertilization rates in irrigation area of the Yellow River. The results indicated that, total amount of AV loss generally increased with the urea application rate in paddy field. During the whole rice growing season,AV loss varied from N 27.6 to 94. 1 kg/ha,which accounted for 16.4%-22.2% of applied N. The AV lasted for 10 days and the peak of AV occurred 2 -3 days after fertilization. Most of the AV loss occurred at the tillering dressing stage, which accounted for 27. 1%-37.0% of the total AV loss throughout the rice growing season. The AV in irrigation area of the Yellow River was affected mainly by temperature,light and pH value. The AV loss has a significant positive linear relationship with the ammonium concentrations in surface water of paddy field. Compared with the local fertilizer application （ N300 ） , optimizing N application （ N240 ） and N fertilizer application a- mended with organic manure （ N240-1/20M ） could obviously reduce the AV loss from the field, meanwhile, get a desirable yield. Based on our experiment, the optimum fertilization formula for the paddy field in irrigation area of the Yellow River is N240 and N240-1/2oM.