Study On Reduced Fertilization And Optimized Fertilization On Winter Tomato In Youjiang River Valley Of Guangxi

Tomato is the vegetable widely cultivated in the world,it is generally considered a nutritious food.There is tradition of planting tomato in.autumn and winter in Youjiang River Valley.Because of its large amount of fertilizer,people tend to pursue high yield and excessive use of chemical fertilizers in the planting process.This not only affects the tomato yield and quality but also bring some environmental pollution problems.Therefore,it is of great practical significance to ensure the sustainable development of the ecological construction and the characteristic industry of Youjiang River Valley in order to reduce,the cost,improve the utilization rate of fertilizer and the tomato yield and quality.Field experiment and the experiment of soil incubating method conducted including five fertilization treatments:T1:Conventional fertilization(top dressing 5 times,fast-release nitrogen fertilizer),T2:Reduced fertilization(top dressing 5 times,fast-release nitrogen fertilizer),T3:Reduced and optimized fertilization I(top dressing 4 times,slow-release fertilizer accounted for total nitrogen 1/5),T4:Reduced and optimized fertilization II(top dressing 3 times,slow-release fertilizer accounted for total nitrogen 2/5),T5:Reduced and optimized fertilization ?(top dressing 2 times,slow-release fertilizer accounted for total nitrogen 3/5).The experiment studies the effects of different fertilization treatments on yield,quality,physiological indicator traits and the situation of nutrient supply.Available nutrient release characteristics of different fertilization treatments were studied by the experiment of "soil incubating method".Results showed that as follows:1.Compared with conventional fertilization(T1),the available nutrient release,available nutrient content in soil and nutrient accumulation in leaves under the reduced fertilization(T2)were lower than that T1,but the difference was not significant.Under the reduced and optimized fertilization(T3,T4,T5),the available nutrient release and available nutrient content in soil was small,the nutrient content in leaves was not significant difference at the early growth period of tomato.Compared with conventional fertilization,the available nutrient release,available nutrient content in soil and nutrient accumulation in leaves under the reduced and optimized fertilization was accelerated at the late growth period of tomato.Therefore,slowed-release fertilizer better satisfied with tomato nutrient uptake than conventional fertilization treatment.2.Compared with conventional fertilization,the reduced fertilization had no significant effect on the NR activity,GS activity,chlorophyll content,photosynthetic parameters and chlorophyll fluorescence kinetics parameters in tomato leaves.Under the reduced and optimized fertilization,the chlorophyll content in tomato leaves were lower than that T1 at the early growth period of tomato.Compared with conventional fertilization,the reduced and optimized fertilization could effectively improve NR activity,GS activity,chlorophyll content,Pn,Fv/Fm,?OPSII and qP of tomato leaves at the late growth period of tomato.The treatment of T5 has the best effect.3.Compared with conventional fertilization,the reduced fertilization can be stable the yield of tomato.The reduced and optimized fertilization could effectively improve tomato yield and income.Compared with conventional fertilization,the treatments of T3,T4,T5 could make the yield of tomato separately increased by 9.69%,7.83%,6.57%;the treatments of T3,T4,T5 could make the yield of tomato separately increased by 10.17%,8.15%,6.75%.The treatment of T3 has the best effect.4.Compared with conventional fertilization,the reduced fertilization and reduced and optimized fertilization could effectively improve tomato the content of soluble sugar,and decreased nitrate content.Compared with conventional fertilization,the treatments of T2,T3,T4,T5 could make the content of soluble sugar separately increased by 4.37%,3.95%,6.65%,5.82%,and make the content of nitrate separately decreased by 5.51%,15.85%,7.06%,10.42%.Compared with conventional fertilization,the treatments of T3,T4,T5 could increased the Vc content,the rate separately by 6.64%,15.15%,9.01%.5.Compared with conventional fertilization,the reduced fertilization and reduced and optimized fertilization could effectively decrease the content of nitrate nitrogen,especially 20 cm below the soil after the harvest.Compared with conventional fertilization,the treatments of T2,T3,T4,T5 could make the content of nitrate nitrogen in 20-40cm soil separately decreased by 59.70%,63.18%,59.70%,47.76%;the treatments of T2,T3,T4,T5 could make the content of nitrate nitrogen in 40-60cm soil separately decreased by 63.30%,56.00%,58.40%,37.60%.The treatment of T2 has the best effect.In summary,the reduced and optimized fertilization with the appropriate proportion of slow-release fertilizer can not only reduce the amount of 20%fertilizer application,and more balanced and stable to ensure that tomato nitrogen,phosphorus and potassium nutrient supply,improve tomato yield and quality,increase economic efficiency.