为了探讨宁夏引黄灌区露地菜田土壤氨挥发损失特征，于2013年5—9月在该区域露地花椰菜－大白菜轮作体系下，采用田间小区试验，研究了不同有机无机肥配施对土壤氨挥发速率、氨挥发损失通量及其损失率的影响。结果表明：露地花椰菜和大白菜基肥后，不同有机无机肥配施处理下土壤氨挥发损失高峰通常出现在第1～4天，而追肥后提前到1～2天，在高量施氮处理下，氨挥发延续时间在10天以上；花椰菜季大多数施肥处理的氨挥发损失发生在追肥阶段（占总氨挥发损失通量的50．2％～60．3％，单施有机肥和低氮处理除外），大白菜季各处理的氨挥发损失主要在基肥阶段（占总氨挥发损失通量的57．0％～73．6％）；露地花椰菜基肥和追肥后，不同施肥处理下土壤氨挥发最大速率分别在0．79～4．56、1．00～5．34 kg · hm－2· d－1之间，而露地大白菜季分别为3．49～13．09、1．54～7．03 kg·hm－2·d－1；不同有机无机肥配施下，花椰菜和大白菜全生育期内土壤氨挥发损失通量分别为5．15～35．82、11．11～70．60 kg·hm－2，其随总施氮量的增加而增加；花椰菜和大白菜季不同施肥处理的土壤氨挥发损失率分别为4．02％～4．87％和2．54％～10．55％，其化肥贡献率分别为62．0％～100．0％和85．5％～100．0％，且化肥贡献率随化学氮肥用量的增加而增加。因此，在同等施用有机肥的情况下，合理降低化肥氮用量是减少该地区露地菜田土壤氨挥发损失的重要措施。%In order to investigate the emission loss characteristics of soil ammonia volatilization in the Yellow River Irrigation Region of Ningxia ,a field experiment was conducted under the rotation system of open field broccoli and Chi-nese cabbage from May to September ,2013 to have studied the effects of different combined applications of organic -in-organic fertilizers on rate of soil ammonia volatilization ,accumulative loss by ammonia volatilization ,and loss ratio of N applied .The results indicated that the peak rates of ammonia volatilization after base fertilization in open field broccoli and Chinese cabbage appeared generally within 1~4 days ,whereas the peak rates anticipated 1-2 days after top dress-ing .Soil ammonia volatilization could sustain more than 10 days with high N application rates .Soil ammonia volatilization happened mostly during top dressing fertilizers treatments in broccoli season (accounted for the total ammonia volatiliza-tion by 50 .2% ~60 .3% ,except for treatments with only manure and low N rate application ) .However ,ammonia pri-marily became lost during base fertilization in Chinese cabbage season (accounted for the total ammonia volatilization by 57 .0% ~73 .6% ) . The maximal rates of ammonia volatilization after base and top dressing fertilizations in open field broccoli ranged from 0 .79~4 .56 and 1 .00~5 .34 kg·hm-2·d-1 ,respectively ,and the corresponding maximal rates in Chinese cabbage ranged from 3 .49~13 .09 and 1 .54~7 .03 kg·hm-2·d-1 ,respectively .In different combined appli-cations of organic-inorganic fertilizer treatments ,accumulative losses by ammonia volatilization during the total growing periods of broccoli and Chinese cabbage ranged from 5 .15~35 .82 and 11 .11~70 .60 kg·hm-2 ,respectively ,which were always elevated with the increase of total N application .The loss ratios of N applied in different fertilization treat-ments ranged from 4 .02% ~4 .87% and 2 .54% ~10 .55% in broccoli and Chinese cabbage seasons ,respectively ,and the corresponding contribution ratios of chemical fertilizers were 62 .0% ~100 .0% and 85 .5% ~100 .0% ,respective-ly .The contribution ratios of chemical fertilizers were upraised with the increase of chemical N application .Therefore , with the application of organic manure at the same level ,it is important to decrease chemical N application ,reducing e-mission loss by soil ammonia volatilization in the open vegetables field in this region .
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