Effect Of Fertilization On The Yield And Qualities Of Chinese Cabbage And Study Of Nitrate Accumulation

The paper take advantage of quadratic saturation D optima design (311B project), and study on the effects of combined application of N,P and K on the yields and qualities of Chinese cabbage, and the effects of combined application organic manure and chemical fertilizers. The purpose is to heighten the content of Vc and lower nitrate content by fertilization under the condition of satisfying the yield of Chinese cabbage, and explore an ideal fertilizer applied model which cut out of product no hazard Chinese cabbage in JiLin Province. The experiment of this paper was carried out in the JiLin Agriculture University from June to October in 2003,We measure the yield, the content of Vc and nitrate content of Chinese cabbage with different fertilization and build up fertilizer applied model and come into the optimum rates of N, P2Os and K2O which gave high yields of Chinese cabbage with good qualities.The results of experiment showed: the yields or qualities of Chinese cabbage which be applied fertilizers are all better than CK, It can improve 30 percent on the yield of Chinese cabbage by combined fertilization. The content of Vc and pure substance all increase too much, but the content of nitrate descend obviously. So the Chinese cabbage which are high yields and good qualities should be applied fertilizers.The extent of P2O5 and K2O are same basically under the condition of satisfying high yield and good qualities of Chinese cabbage by the equation between fertilization and the yield, the content of Vc, nitrate content, but nitrogen is different. By the experiment , think about the optimum economic utility and not exceed the limit of danger ( 1440mg/kg),Obtain the optimum extent of Chinese cabbage GS80 is N245 ~ 265kg/hm2 , P2O5158 - 188kg/hm2 , K2O150 ~ 165kg/hm2 , N:P2O5:K2O=1:0.68:0.62, the forecast yield is 119620kg/hm2, the content of Vc is 272.14mg/kg, and nitrate content is 1051.67 mg/kg; and the optimum extent of Chinese cabbage WFCW is N210~230kg/hm2, P2O5170~ 190kg/hm2, K2O150~ 180kg/hm2, N:P2O5:K2O=1:0.82:0.75, the forecast yield is 150590kg/hm2, the content of Vc 276.92mg/kg, nitrate content is 1021.82 mg/kg,The same tendency was showed in the yields and the qualities of Chinese cabbage GS80 or WFCW by combined fertilization, but there are some differences onthe yields and quality between them on the same condition of water and fertilizers, it is probably determined by the gene. But to any kind of Chinese cabbages, there is probable a contradiction between high yield and good quality. So in the actual production, we must select some kinds whose good genetic characters.The experiment showed, combination of organic manure and N, P2O5 and K2O not only can increase yield ,but also can improve qualities of Chinese cabbage. The ideal rates of organic manure and inorganic fertilizers are 1:1 ~ 1:2.The nitrate content and NR have too many correlations in the Chinese cabbage by the experiment of the different kinds of Chinese cabbages. NR is an inductive enzyme, it is from gene impart to express needing induction of NOs'.So NR is an important factor accelerating nitrate conversion. But the more profound research need carry out on the aspect in the future.The experiment show: after the Chinese cabbages have been preserved or stored up for a long time, the content of nitrate accumulation has been descent too much. It has been measured up the national criterion about taking away. But nitrite content increase too much and exceed 0.13mg/kg.The people should lessen to eat the preserved Chinese cabbages. With standard of living improved, more and more demands on good qualities of Chinese vegetables, the Chinese cabbage which been applied fertilizers will not endanger the people's health as long as eating appropriately.