不同氮肥利用效率水稻品种开花后地上部分氨挥发研究

Ammonia Volatilization from Shoots of Different Rice Genotypes with Different Nitrogen Use Efficiency after Flowering

采用密闭生长箱法研究了4个不同氮肥利用效率水稻品种开花后地上部的氨挥发损失。结果表明：尽管单位时间内不同水稻品种叶片氨挥发的数量存在差异，但各品种均呈现类似的昼夜变化规律，即白天叶片氨挥发的数量较高，夜晚（0：00～8：00）叶片氨挥发量显著下降。开花期是水稻全生育期中叶片氨挥发量最大的时期，其释放的氨占总挥发量的14％～16％。开花至成熟期地上部氨挥发的动态和氨挥发总量，不同氮效率水稻品种间存在显著差异，且氨挥发总量（y）与水稻氮肥利用率（x）存在极显著负相关：y=13．075-0．00968x（r=-0．9913^＊＊，n=4）。锡稻11生物量最小，其氨挥发量却最大；而地上部生物量较大的3010和武粳4号氨挥发量却较小，暗示不同品种间氨挥发的差异并非源于水稻地上部生物量的不同。

Ammonia volatilization from shoots of four rice genotypes （i. e. 3010, 3030, Wujing 4 and Xidao 11） with different fertilizer-N use efficiency was assessed by close chamber method after flowering. Significant variance of ammonia volatilization from these genotypes was observed in a day, whilethe diurnal fluctuation law was similar. The amount of ammonia volatilization from 0 ： 00 to 8 ： 00 a.m. was significantly less than that in the daytime. The amount of ammonia volatilized from shoots was higher at flowering than at any other stages. Significant variance could be observed in the total amount of ammonia volatilization from the aboveground of these four genotypes after flowering. There was a significant negative relationship between the utilization rate of nitrogen of rice（y） and the amount of ammonia volatilization（x）： y= 13. 075- 0. 00968x （r= -0. 9913^＊＊ , n=4）. The shoot dry weight of Xidao 11 was the lowest among the four genotypes, however the overground ammonia loss was the highest, suggesting that the difference of shoot biomass was not the main cause of ammonia volatilization from these genotypes.