在田间条件下,用~(15)N标记的微区试验法研究了潮土-冬小麦系统中尿素的转化和化肥氮的去向。结果表明:土壤中尿素水解后,主要进行硝化和生物固定,而被粘土矿物固定的量很少;小麦返青后,随着气温上升,生物固定的标记氮不断分解,其量可达总生物固定量的60％。作为基肥条施的尿素,其损失略高于作返青肥或拔节肥表施后随即灌水的处理。氮素损失主要发生在春季气温回升后的生长期间,当季的淋洗损失极微。在较为适宜的用量和施用技术下,化肥氮的损失仍达33—45％,其中以碳酸氢铵为最高,次为硫酸铵和硝酸铵,而尿素和硝酸铵中的硝态氮损失最低。 Under field conditions, urea conversion and fate of fertilizer N were studied in the micro-plot test with ~ (15) N. The results showed that after the hydrolysis of urea, nitrification and biotransformation were mainly carried out, while clay minerals were immobilized to a small extent. After the wheat was rejuvenated, the biologically immobilized labeled nitrogen could be decomposed continuously with the increase of temperature, 60% of the amount. Urea as a basal fertilizer application, the loss is slightly higher than for the green or jointed fertilizer fertilizer application immediately after the treatment of irrigation. Nitrogen losses mainly occurred during the spring after the temperature rise after the rise, the season of the leaching loss is minimal. Under the appropriate dosage and application technology, the loss of nitrogen fertilizer still reached 33-45%, of which ammonium bicarbonate was the highest, ammonium sulfate and ammonium nitrate times were the second, while the nitrate nitrogen loss was the lowest in urea and ammonium nitrate.