氮素对番茄叶片生理活性的作用研究

以不施氮肥和普通尿素作对照，试验施用两种树脂包膜尿素，整个生育期内跟踪调查了温室盆栽番茄功能叶片的叶绿素含量、硝酸还原酶活性及光合速率，结果发现：过量施用尿素可提高番茄叶片叶绿素含量和硝酸还原酶活性，但降低了其光合速率；氮素对番茄叶片生理功能影响较大，普通尿素导致番茄不同生育期的叶片生理活性变化较大，树脂包膜尿素处理则相对较为稳定，变化量小；两种树脂包膜尿素混用，番茄叶片生理活性维持在相对较高且稳定水平。

Study on the effect of nitrogen on tomato leaves' functions

With the contract of no nitrogen, the effect of N in usual urea(applied by 4 times) and tow kinds of resin-coated urea(applied one time) on the leaf function of greenhouse tomato were tested. The results show that excessive nitrogen can increase the level of chlorophyll and the activity of nitric revert enzyme in tomato leaves, but notablely decreased the rate of photosynthesis; urea made leave function fluctuate with time, but resin-coated urea not so severity; the mixture of this two kinds of resin -coated urea maintained the leaf physiological function at a relative stable and high level.