茶树氮磷钾营养的品种间差异 Ⅰ.氮肥在茶树品种间的生长和生理效应

采用大田和盆栽试验相结合的方法,研究了氮素对茶树不同品种在产量、品质及生长、生理上的效应。结果表明,适量的施氮对各品种的产量和品质均有较好的促进作用,而过量施氮则对品质不利,肥料增产率也下降。过量的氮肥还会使茶树产生肥害,其中苹云、碧峰等大叶品种尤为敏感,而肥害又只能经过茶树自身的生长稀释才能解除。施氮后,新梢叶片中的硝酸还原酶活性、叶绿素含量和含氮化合物含量在小叶品种中增加的幅度较大,而淀粉和蛋白质含量的增加在品种间并未表现出明显的规律,可溶性糖的含量反而下降。此外,还对茶树氮素营养品种间差异的原因以及

Different Responses to the Nutritions of Nitrogen(N) Phosphorus(P) and Potassium(K) Among Various Cultigens of Tea 1.Growing and Physiological Responses to the Nitrogen Applied

Effect of the applied nitrogen on the yield,growth and physiology ofseveral cultigens of tea were studied with field and pot grown plants.Results showed that proper amount of the nitrogen applied was benefitialto both quality and quantity of the fresh leaves,whereas over applyingwas unbenefitial to the quality and would decline the yield-increasingefficiency of the nitrogen applied.The injury caused by excessive nitrogencould only be overcome by the growth dilution of the plants over a periodof time.Results also showed that Pingyun and Bifeng,the two macrophyllcultigens,were more sensitive to and easily injured by excessive nitrogen,while the microphyll cultigens of Longjing 43 and Zhishun yielded more atthe same level of nitrogen.Compared with macrophyll cultigens,themicrophyll responsed more positively to nitrogen in the in vivo nitratereductase activity,the chlorophyll content and the nitrogen compound.The content of soluble carbonhydate decreased at the same nitrogensituation and no significant trend was found for the increases of starchand protein contents in various cultigens.Causes of the different responsesamong the various cultigens and measurements to increase the efficiencyof the nitrogen applied were also discussed in the paper.