华北平原冬小麦-夏玉米轮作体系氮肥的氨挥发

 利用可多点原位测定氨挥发的风洞系统,监测了华北平原2002～2004年冬小麦-夏玉米轮作体系传统和优化氮肥管理下的氨挥发损失.结果表明,氨挥发主要发生在施肥后2～3周内,以施肥后连续采样15d的氨挥发累积量作为总排放量,相同施氮量下生长季夏玉米的氨挥发大于冬小麦.优化处理的氨挥发平均损失率(35.9%)显著高于传统处理(20.9%),但从氨挥发绝对量上看,传统处理为125.1kgN/hm²,优化处理为42.3kgN/hm²,降幅达66.2%.施肥和灌水方式显著影响氨挥发,撒施碳铵后翻耕的氨挥发损失为10.1%,追肥撒施的氨挥发损失平均为24.6%;撒施尿素后立即灌水,氨挥发损失为19.7%,5h后灌水氨挥发损失为34.0%,增加了72.6%.

Ammonia volatilization from nitrogen fertilization of winter wheat-summer maize rotation system in the North China Plain

Ammonia volatilization (AV) losses from traditional and optimized nitrogen fertilizer (NF) management of 2002~2004 Year winter wheat-summer maize rotation system in the North China Plain were monitored under field conditions, using a wind tunnel system. AV occurred mainly in 2~3 weeks after fertilization, using the AV accumulated amount of 15d continuous sampling after fertilization as total losses, under the same N fertilization amount, the AV of summer maize growth season was greater than that of winter wheat season. The AV average loss rate of optimized treatment (35.9%) was higher markedly than that of traditional treatment (20.9%), but view from AV absolute amount, traditional treatment was 125.1kg N/hm2, optionized treatment was 42.3kg N/hm2, showed reduction of 66.2%. Fertilizing and irrigating ways influenced AV. After broadcasting and turnover farming of NH4HCO3, AV loss was 10.1%, the AV loss of top dressing was 24.6% in average; irrigating immediately after broadcasting of urea, AV loss was 19.7%, irrigating after 5h, AV loss was 34.0%, increasing 72.6%.