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在温室粉壤土进行了两个烟草试验,以确定土壤酸度、氮肥种类及磷素对烟草的生长和矿质营养的影响.研究结果表明、施NH_4~+可使根际pH降低0.4～0.6,而NO_3~-则使pH升高,但升高值不足0.1.施NH_4~+后的烟草其早期生长慢于施NO_3~-的烟草.在第一个试验中,烟草体内的磷不受氮肥种类的影响,而在第二个试验中,不论是否施磷,施入NH_4~+均提高了烟草体内磷的浓度及其生物量.烟草体内磷的浓度主要受土壤pH的制约,当pH=6.2时达到最大值,高于或低于此值,磷的浓度均会下降.烟草体内钼的浓度在pH=5.4时不随施氮种类的不同而发生变化,但当pH=7.2时,施NO_3~-则可使钼的浓度提高为前者的三倍.施钼的处理施磷可提高烟草内钼的浓度,不施钼时,施磷则不提高铝的浓度.磷和钼的这种关系是建立在施氮且NH_4~+多于NO_3~-的基础之上的.结果表明,当土壤中氮的水平足够高时,施磷可改善烟草钼的营养.
Two tobacco experiments were carried out in the greenhouse soils to determine the effects of soil acidity, nitrogen fertilizer and phosphorus on the growth and mineral nutrition of tobacco. The results showed that rhizosphere pH decreased by 0.4-0.6 NO_3 ~ - increased the pH but increased the value less than 0.1. The early growth of NH_4 ~ + tobacco was slower than that of NO_3 ~ .In the first experiment, the phosphorus in tobacco was not affected by nitrogenous fertilizer , While in the second experiment, the application of NH4 + increased the concentration of phosphorus and its biomass in tobacco with or without phosphorus application.The concentration of phosphorus in tobacco was mainly controlled by the pH of the soil, and when pH was 6.2 Reaches the maximum, above or below this value, the concentration of phosphorus will decrease.The concentration of molybdenum in tobacco does not change with the type of nitrogen at pH = 5.4, but when pH = 7.2, - the concentration of molybdenum can be increased to three times that of the former.Phosphorus treatment can improve the concentration of molybdenum in tobacco.With the absence of molybdenum, phosphorus does not increase the concentration of aluminum.The relationship between phosphorus and molybdenum is Was established on the basis of applying nitrogen and more NH_4 ~ + than NO_3 ~. The results showed that when the level of nitrogen in soil was high enough, Nutrition molybdenum.