Study On Effects Of Zinc And Manganese Fertilizers Cooperating Application On Yield, Quality And Physiological Index Of Chinese Cabbage

Zinc and manganese are essential microelements for the growth and development of crops.In recent years,excessive use of nitrogenous and phosphorous fertilizer and no or less use microelement fertilizer has resulted in surplus of N and P and lack of certain microelement in vegetable land of China,and that has become the limiting factor of increasing crop yield and quality.In the experiment,zinc fertilizer(zinc sulfate) and manganese fertilizer(manganese sulfate) had 30 kg·hm^-2,75 kg·hm^-2 and 120 kg·hm^-2 three lever respectively,therefore all zinc fertilizer together with manganese fertilizer were 9 combinations.The effect of zinc(Zn) and manganese(Mn) fertilizer cooperating application on Chinese cabbage(Brassica campestris L.ssp.Chinensis) planted in calcareous cinnamon soil were studied in order to find the optimal combination of zinc and manganese.The results showed that:1.Zinc(Zn) and manganese(Mn) fertilizer cooperating application can significantly increase the SOD,POD,CAT activity and reduce the MDA content.The increase of these antioxidant enzymes activities and reduce of MDA content can enhance the antioxidant capacity of plant,improve the resistance and delaying the senescence of plant.The SOD activity of Zn₂Mn₂ was the highest.The POD activity of Zn₃Mn₂ was the highest.The CAT activity of Zn₃Mn₃ was the highest.The MDA content of Zn₂Mn₂ was the lowest.2.Zinc(Zn) and manganese(Mn) fertilizer cooperating application can significantly increase the chlorophyll content,stomatal conductance,transpiration rate and net photosynthetic rate of Chinese cabbage,consequently promote the synthesis and metabolism of carbohydrates.The chlorophyll content of Zn₃Mn₂ combination was the highest.The stomatal conductance,transpiration rate and net photosynthetic rate of Zn₂Mn₂ combination were the highest.3.Zinc(Zn) and manganese(Mn) fertilizer cooperating application can significantly increase the yield of Chinese cabbage,and the effect of zinc fertilizer was greater than that of manganese fertilizer.The yields of Zn₃Mn₂,Zn₃Mn₃,Zn₂Mn₃,Zn₂Mn₂ combination were 42.9%,42.0%,40.7%,38.7%higher than that of control(Zn₀Mn₀) respectively and the difference between them were not significant.4.Zinc(Zn) and manganese(Mn) fertilizer cooperating application can raise the nitrate reductase(NR) activity.The nitrate reductase activity of these 9 combinations of zinc and manganese were 19.1%～105.7%higher than that of control,and the NR activity of Zn₃Mn₃ was the highest.The nitrate reductase activity was stronger raised by manganese than zinc. The nitrate content of these 9 combinations were 2.0～27.2%lower than that of control.the nitrate content of Zn₃Mn₃,Zn₂Mn₃,Zn₃Mn₂ combinations were the lowest and the difference between them were significant.5.Zinc(Zn) and manganese(Mn) fertilizer cooperating application can significantly increase the content of zinc and manganese of Chinese cabbage.The zinc content of tested combinations were 87.7～158.8 mg·kg^-1 and 120.9%～300.0%higher than that of control. The manganese content of tested combinations were 83.7～104.5 mg·kg^-1and 12.8%～40.8% higher than that of control.6.Every combination of zinc and manganese fertilizer cooperating application can significantly improve the quality of Chinese cabbage.The Vc(antiscorbutic vitamin)content of these 9 combinations were 16.3%～58.7%higher than that of control.the Vc content of Zn₃Mn₃,Zn₃Mn₂,Zn₂Mn₃ combinations were the highest and the difference between them were not significant.The reducing sugar content of these 9 combinations were 29.1%～64.5%higher than that of control.the reducing sugar content of Zn₃Mn₃,Zn₃Mn₂,Zn₂Mn₃ combinations were the highest and the difference between them were not significant.7.Zinc fertilizer and manganese fertilizer had interaction on the yield,quality and the observed physiological index.Summarized above results,we found that the optimal combination of zinc and manganese to obtain Chinese cabbage with high yield and quality was 75～120 kg·hm^-2 zinc sulfate together with 75 kg·hm^-2 manganese sulfate。...