太湖地区冬小麦季土壤氨挥发与一氧化氮排放研究

采用密闭室连续抽气法和静态箱法同步研究了太湖地区冬小麦季田间小区试验中不同施氮处理的氨挥发与一氧化氮（NO）排放的规律。结果表明，麦季氨挥发主要发生在施肥后 7～10d，以基肥期挥发量最大，为NH3-N 0.49～9.36 kg/hm2，占整个麦季观测期间挥发量的60.4%～74.7 %；NO的排放则主要发生在施用基肥后的30d 内，量虽小但持续时间较长，排放速率为NO-N 0.009～0.304 mg/(m2.h)，该时期总损失量为NO-N 0.68～1.23 kg/hm2，约占整个麦季观测期排放量的 93%。氨挥发和 NO 排放均随施氮量的增加而增加。各施氮处理麦季观测期的氨挥发总损失量为NH3-N 7.6～12.6 kg/hm2，损失率4.62%～5.26%；NO排放总量为NO-N 0.73～1.3 kg/hm2，损失率0.27%～0.41%。研究结果对综合评价太湖地区麦季氮肥的气态损失及其环境效应、指导合理施肥都具有重要意义。

Ammonia volatilization and nitric oxide emission from soil during?winter wheat season in Taihu Lake region

Field experiments were conducted to evaluate N losses from ammonia volatilization and nitric oxide emission in wheat growing season with different rates of N application in Taihu Lake region. Ammonia volatilization was measured with the continuous airflow enclosure method, while nitric oxide with the static transparent chambers. The results show that the ammonia volatilization in wheat season mainly occurs during the first 7-10 days after each application of fertilizer. Basal fertilization is the main loss stage of ammonia volatilization whose loss varies from N 0.49-9.36 kg/ha which accounts for 60.4% to 74.7% of the wheat observation period. The nitric oxide emission in respond to the urea application mainly takes place during the 30 days after the basal fertilization, the rate of emission is NO-N 0.009-0.304 mg/(m2h), and the accumulative loss is NO-N 0.68-1.23 kg/ha, which accounts for 93% of the total loss during the observation period. The amounts of nitric oxide emission and ammonia volatilization positively correlate with the rate of N application. The accumulative losses from ammonia volatilization during the wheat observation period range from NH3-N 7.6 kg/ha to 12.6 kg/ha, which accounts for 4.62% to 5.26% of the total amount of N application, while the nitric oxide emissions range from NO-N 0.73 kg/ha to 1.3 kg/ha, the loss rates are 0.27% to 0.41%. The results are valuable for evaluating the gaseous loss and environmental effects in wheat season, and have significant meaning for directing rational fertilization.