Effects Of Phosphorus And Potassium Fertilizer On Yield And Quality Of Dwarf Rootstock Apple Trees Under Drip Irrigation

In order to study the effects of phosphorus and potassium fertilizer application on the physiological growth,yield and quality of dwarf anvil apple tree,this experiment used the phosphorus and potassium topdressing amount as the control factor,and set six treatments:T1(P1K2)、T2(P2K2)、T3(P3K2)、T4(CK)、T5(K1P2)and T6(K3P2),each treatment was repeated three times,among which:P1,P2 and P3 represent the total amount of phosphate topdressing fertilizer with 49kg/hm~2,70 kg/hm~2 and 91kg/hm~2 respectively,and K1,K2 and K3 represent the total amount of potassium topdressing fertilizer with 70kg/hm~2,100kg/hm~2 and 130kg/hm~2 respectively.T4 represent the surface irrigation control group(CK)with the total amount of phosphate topdressing fertilizer and potassium topdressing fertilizer P2 and K2 respectively.During the experiment,the physiological growth indexes of fruit trees were measured regularly,and their yield and quality indexes of the fruit trees were measured at the end of the growth period and then the irrigation and fertilization scheme suitable for the growth and high yield of dwarf anvil apple trees was obtained by comprehensive analysis.The main conclusions of this study are as follows:1.The Study on the Effect of Drip Irrigation Phosphorus and Potassium Fertilizer on Water and Fertilizer Distribution Characteristics in Soil.(1)Under drip irrigation,soil volumetric moisture content first increases and then decreases with the increase of soil depth,while under surface irrigation,soil volumetric moisture content gradually increases with the increase of soil depth.Under drip irrigation,soil volumetric moisture content first increases and then decreases with the increase of radial distance.Under surface irrigation,there is no significant difference in soil volumetric moisture content at different radial distance.(2)The vertical distribution characteristics of available phosphorus content in soil of different treatments are basically the same,which all decrease with the increase of soil depth.The characteristics of dynamic change of available phosphorus content in different layers of soil were consistent and showed a gradual increasing trend with the growth period.The content of available phosphate was higher in the 0~20cm soil layer treated by drip irrigation P2K2,and higher in the 60~80cm soil layer treated by surface irrigation.(3)The vertical distribution characteristics of available potassium content in soil under different treatments were basically consistent,and all showed a decreasing trend with the increase of soil depth.The dynamic variation characteristics of available potassium content in different soil layers were different from each other.The available potassium content was higher in the 0~40cm soil layer treated with drip irrigation P2K2,and higher in the 40~80cm soil layer treated with surface irrigation.2.The Study on Effects of Drip Irrigation with Phosphorus and Potassium Fertilizer on Physiological Growth of Dwarf Anvil Apple Trees.During the whole growth period,the average leaf water potential value of P2K2 treatment was the highest,which was 16.8%,18.7%,21.6%,12.4%and12.3%higher than that of P1K2,P3K2,K1P2,K3P2 and CK treatment,respectively.P2K2 treatment has the largest cumulative growth rate of new shoots,which is 17.3%,12.9%,18.8%,8.7%and 10.4%higher than P1K2,P3K2,K1P2,K3P2 and CK treatment,respectively.The cumulative increase of trunk diameter was the largest under P2K2 treatment,which was 30%,7%,44%,18%and 21%higher than that under P1K2,P3K2,K1P2,K3P2 and CK treatment,respectively.The mean net photosynthetic rate of leaves treated with P2K2 was the largest,which was 10%,12%,9%,6%and 12%higher than that treated with P1K2,P3K2,K1P2,K3P2 and CK,respectively.Compared with P1K2,P3K2,K1P2,K3P2 and CK,the mean stomatal conductance of leaves treated with P2K2 was the largest,which was 9%,10%,8%,4%and 12%higher,respectively.Compared with P1K2,P2K2,P3K2,K1P2 and K3P2,the average intercell CO2 concentration in leaves treated with CK was the largest,which was 6%,4%,3.7%,5%and 2.7%higher,respectively.Compared with P1K2,P3K2,K1P2,K3P2 and CK,the transpiration rate of leaves treated with P2K2has the largest mean value,which is 2%,1.4%,1.5%,0.1%and 4.5%higher,respectively.Compared with P1K2,P3K2,K1P2,K3P2 and CK,P2K2 treatment had the largest mean water use efficiency,which was 7.7%,9%,7.4%,5.5%and9.1%,respectively.Under drip irrigation,the trunk and stem flow rate treated by P2K2 was higher than that treated by CK.3.The Study on Effect of Drip Irrigation on Yield and Quality of Dwarf Anvil Apple TreesThe single fruit weight,optimum fruit rate,colouring index and soluble solid content were the largest and the acidity was the least by K3P2treatment.The maximum number of fruits and the maximum fruit shape index,flesh firmness and yield are processed by P2K2.The fruit quality treated by drip irrigation P2K2 was significantly better than that treated by surface irrigation CK.4.The Study on Multi-layer Fuzzy Analysis and Comprehensive Evaluation of Fruit Yield and Quality Index.In this paper,a comprehensive evaluation model of apple tree yield,single fruit weight,optimum fruit rate,fruit shape index,flesh hardness,colouring index,soluble solid content and acidity was established through drip irrigation and fertilization experiment in dwarf anvil apple trees.besides the Comprehensive scores of various treatment methods were obtained through fuzzy level comprehensive evaluation,and the optimal phosphorus and potassium fertilizer irrigation scheme under drip irrigation was defined as P2K2.The results of this study can comprehensively reflect the influence of drip irrigation on yield and quality of dwarf anvil apple trees,which is in line with the actual situation of field irrigation and fertilization.