【作者】 刘运通；

【导师】 李玉娥； 陈德立；

【作者基本信息】 中国农业科学院 ， 作物气象学， 2011， 博士

【摘要】 我国氮肥施用过量,利用率低,使农田土壤成为重要的N₂O排放源。为提高氮肥利用率,减少农田N₂O排放,本试验研究了九种肥料处理对山西榆次春玉米2007～2010年生长季内土壤N₂O排放的影响,并结合作物产量探索减少N₂O排放的措施。手动静态箱法测定频率低,易漏掉N₂O排放峰。为提高测量质量,本研究利用自动观测系统进行连续观测。利用试验数据校正、验证水氮管理模型（WNMM）并增加包膜肥料N₂O排放模块,寻找合适的管理措施。主要的研究结果如下:1、2007～2009年开展了传统施肥（T）和优化减氮（O）施肥对比研究。结果得出O处理在减少氮肥施用量64%的情况下,年均N₂O减排48%,且并未减产。土壤水分和土壤铵态氮含量是N₂O的主要驱动因子。沟施追肥要避开强降雨和立即灌溉,是减少N₂O排放的主要措施。N₂O吸收现象主要发生在玉米生长后期,土壤矿态氮含量小于46.4 mg kg^-1时。2、2009年开展了不同氮磷肥对N₂O排放影响的研究,设有空白（CK）、尿素（U）、尿素加磷肥（NP）和硝酸磷肥（NOP）四个处理。结果得出各处理N₂O排放系数分别为U:0.55%,NP:0.4%,NOP:0.27%。尿素加磷肥较单施尿素有助于减少农田N₂O排放,硝酸磷肥较尿素可以显著减少N₂O排放。与U和NP处理相比,NOP处理可减少农民肥料投入15%和30%,降低N₂O排放42%和26%,且未减产。3、2009年开展了不同缓/控释肥对N₂O排放影响的研究,设有不施肥（CK）、尿素（U）、硫包衣尿素（SCU）、硝化抑制剂双氰胺DCD+尿素（UDD）和DCD+碳酸氢铵（ADD）五个处理。结果得出各处理N₂O的排放系数为0.15%～0.55%,小于IPCC推荐的1%;硫包衣肥料N₂O减排效果最好,且产量极显著高于其它各施肥处理（P<0.01）。硝化抑制剂DCD对土壤硝化作用有较高的抑制作用,显著减少了N₂O排放。4、根据T和O处理3年的试验数据,校正和验证了水氮管理模型（WNMM）。结果得出校正、验证后WNMM模型可以模拟春玉米土壤N₂O排放和土壤水分、温度和矿态氮的变化。利用验证后的WNMM模型模拟了891种水肥管理情景,得出普通肥料最佳管理措施为:基肥为硝酸磷肥(73.75kg N hm^-2),追肥为尿素(129.92 kg N hm^-2),播种前和追肥后各灌溉一次,每次灌溉量为100mm。5、基于硫包膜处理下两年（2009～2010）的试验数据和验证后的WNMM模型增加了包膜控释肥模块。结果表明,只有S型曲线法与所有评价指标均显著相关（P<0.05）。综合比较SCU、BMPs、T和O处理得出,硫包衣处理较其它三个处理分别减排N₂O（21.8%～46.8%）、增产（-0.48%～22.2%）、增收（1.8%～28.3%）,因此硫包衣肥料是减少春玉米N₂O排放的最佳选择。更多还原

【Abstract】 Excessive nitrogen fertilizer application results in the lower nitrogen fertilizer use efficiency and cropland becomes an important source of N₂O emission. In order to increase the nitrogen fertilizer use efficiency, reduce the N₂O emissions, a field experiment was undertaken during spring maize growing season from 2007 to 2010 at Yuci, Shanxi Province, in North China, to investigate the effects of nine fertilizer treatments on N₂O emissions from spring maize soil, the responses of grain yield, in addition to N₂O emissions, were examined to explore feasible strategies to reduce N₂O emission. Low frequence of the manual measurement by static chamber may miss the N₂O peak emissions. During this research an automated measurement system was taken to improve the quality of N₂O monitoring. Based on the obersvered data to calibration and validation the Water and Nitrogen Management Model （WNMM） and add a mode to simulation the N₂O emission from sulfure coated urea to get the suitable option.The main results are as follows:1. Compared the effect of Traditional （T） to Optimal of nitrogen reduction treatments （O） on N₂O emission from 2007 to 2009. The results showed that the Optimal of nitrogen reduction treatment was a better choice, compare to Traditional treatment, produced the same yield of grain, and significantly reduced N₂O emissions by 48% on average every year, while reduce nitrogen fertilizer input by 64%. The WFPS and soil NH4+ content were identified as the major environmental factors controlling N₂O emissions from the soil every year. Banding with fertilizer should not during periods of heavy rainfalls and no irrigation immediately were devised as the feasible strategies to reduce N₂O emissions from spring maize in North China. N₂O uptake occurred mainly during the late stage of spring maize growth when the soil mineral N content was less than 46.4 mg kg^-1 soil.2. Study the effect of different nitrogen and phosphorus fertilizers on nitrous oxide emissions from spring-maize field in 2009. Four fertilization management practices were selected, viz. zero fertilizer as control treatment （CK）, urea treatment （U）, urea and phosphorus treatment （NP）, nitric phosphate treatment （NOP）. The results indicated that the emission factors of each treatment were U（0.55%）,NP（0.4%） and NOP（0.27%） respectively. Compared to urea treatment not only urea and phosphorus could reduce the N₂O emissions, but also the nitric phosphate treatment could significantly reducing the N₂O emissions. NOP treatment was a better management practice in the sense that, when compared to U and NP treatments, it reduced not only N₂O emission by 42% and 26% separately, but also farmers’expenditure on fertilizers by 15% and 30%, while maintaining crop yield.3. Study the effect of different slow/control release nitrogen fertilizers on nitrous oxide emissions from spring maize field in 2009. Five fertilization management practices were selected, viz. （1） zero fertilizer application as control （CK）, （2） urea （U）, （3） sulfur-coated urea （SCU）,（4） nitrate inhibitor dicyandiamide （DCD） with urea （UDD） and （5） DCD with ammonium bicarbonate （ADD）, The results indicated that the N₂O emission factor （EF） of every fertilizer treatment was between 0.15%⁰.55%, lower than 1% which was suggested by the Intergovernmental Panel on Climate Change （IPCC）. The sulfur-coated urea was most effective in reducing N₂O emissions, and the yield obtained under SCU was significantly higher than other four treatments （P<0.01）. Nitrate inhibitor DCD was effective in reducing soil nitrification, which could significantly reduce N₂O emissions.4 Calibration and validation WNMM model and determining the BMPs based on the T and O treatments. The results indicated that the calibrated and validated WNMM model satisfactorily simulated soil mineral N contents, soil water content, soil temperature and N₂O emissions from the spring maize soil, compared with the field observations during calibration and validation. Results showed that the BMPs under normal fertilizer type were using nitric phosphate (73.75kg N hm^-2) as basal fertilizer and urea (129.92 kg N hm^-2) as banding with fertilizer, with irrigation of 100mm twice （one before tillage and one after banding with fertilizer）.5. Add the SCU mode based on the field observed data under SCU treatment from 2009 to 2010 and the calibrated and validated WNMM model. The results showed that the S curve method was the best choice for the SCU mode, which had a significant relationship with all of the assessment index （P<0.05）. Compared the performance of the four treatments （SCU, BMPs, T and O） under history 59 years weather data, and the results showed that the SCU performed better than BMPs, T and O treatments, which reduce N₂O emission from 21.8%～46.8%, increased yield from -0.48%～22.2% and net return from 1.8%～28.3%. So the sulfur coated urea was the best choice for the spring maize field in North China.更多还原