Study On Recommended Fertilization Of Adult Walnut In Yecheng,Xinjiang

Xinjiang is the main walnut producing area in the northwest arid region.In 2020,the walnut planting area is 391,100 hm²,of which Yecheng walnut area is 37,400 hm²,accounting for 9.5%.In the current Yecheng walnut production process,there are still problems such as unclear nutrient requirements,extensive fertilization management,high fertilizer and low efficiency.In view of this,the research on recommended fertilization of walnut has important practical significance for guiding farmers to apply fertilizer scientifically and developing regional industries.The research first collected the literature data of walnut nutrient absorption and yield paramete rs in my country from 2000 to 2019.According to the division of the main walnut producing area s,the nutrient absorption curve was constructed by using the Solver method,and the walnut nutrie nt absorption threshold in each region was calculated.As the basis,combined with soil fertility an d the residual amount of the previous season,determine the optimal amount of fertilization in the field test,and then set up a"3414+2"test with walnuts in Yecheng County,Xinjiang as the resear ch object（that is,the 3414 whole area test+soil fertility grading method+Farmers are used to fertilization method）for field verification.A total of 16 treatments were set up in the experiment:N₀P₀K₀（no fertilization）,N₀P₂K₂,N₁P₂K₂,N₂P₀K₂,N₂P₁K₂,N₂P₂K₂,N₂P₃K₂,N₂P₂K₀,N₂P₂K₁,N₂P₂K₃,N₃P₂K₂,N₁P₁K₂,N₁P₂K₁,N₂P₁K₁,FP（farmers’customary fertilization method）,Soil grading method,soil fertility Grading method,by studying the effects of different nitrogen,phosphorus and potassium applicati on rates on walnut soil nutrients,plant nutrient absorption,yield and quality,a regression fitting fe rtilizer efficiency equation was established to solve the optimal fertilizer rate under the highest yiel d and economic yield,with a view to guiding Yecheng The scientific fertilization of mature walnut s provides a reference.The test results are as follows:1.Solver partition analysis results show that there are differences in walnut nutrient uptake in different regions.The ratios of nitrogen,phosphorus and potassium uptake in the northwest,southwest,eastern coastal and central regions are 1:0.65:0.85,1:0.83:0.85,1:0.76:1.04 and 1:0.55:0.59,the recommended fertilization plan setting should comprehensively consider the differences in regional absorption laws.2.The following results were obtained in the field 3414+2 test:（1）Effects of different fertilization on soil nutrients:Through soil nutrient analysis,the soil fertility in this experimental area was at the middle and lower levels.Among them,the highest contents of total nutrients N,P and K were 0.4,0.5,17.15g/kg,and the organic matter was 7.6g/kg;the highest contents of alkaline hydrolyzable nitrogen,available phosphorus and available potassium in the available nutrients were 19.77,16.38,and 200 mg/kg,respectively.Further correlation analysis showed that each nutrient parameter had the most significant correlation with organic matter,and the content of organic matter was an important indicator for improving soil fertility.（2）The fitting equation of SPAD value of walnut leaves,leaf nutrients and fertilization rate was established:when the upper limit of SPAD value was determined by the equation,the application rate of N in the expansion period,hard core period and harvest period was 0.42,1.06,0.49kg/plant;According to the SPAD high limit value,the nutrient situation of nitrogen excess or lack can be fed back,and nitrogen fertilizer application can be adjusted in time.In addition,the fitting degree of N fertilizer and leaf nitrogen content equation was significantly correlated,so it was estimated that when N fertilizer was 0.48kg/plant,the leaf total nitrogen content reached a maximum of 16.75g/kg.（3）The relationship between yield,quality indicators and fertilization amount was clarified:The ternary quadratic fertilizer efficiency equation between yield and NPK fertilizer amount was established,and the N,P₂O₅,K₂O application amounts were calculated to be 0.32,0.61,0.59 kg/plant,the highest yield is 8.90kg/plant;considering the walnut price and input cost,the calculated economic yield is 8.89kg/plant,and the corresponding application rates of N,P₂O₅,K₂O are 0.21,0.59,0.58kg/plant,and the ratio is1:2.8:2.7.（4）Combined with the processing requirements of walnuts,with crude protein and crude fat content as indicators,the optimized application rates of N,P₂O₅and K₂O were 0.65kg/plant,1.24kg/plant,0.73kg/plant and 0.52kg/plant,respectively.1.37kg/plant,0.99kg/plant.To sum up,it is suggested that the recommended fertilization scheme for high yield of mature walnuts in Yecheng County adopts N0.21kg/plant,P₂O₅0.59kg/plant and K₂O0.58kg/plant,and the application ratio is 1:2.8:2.7.The ratio is 21%in the expansion period,54%in the hard core period,and 25%in the harvest period.With the demand for improving the quality and efficiency of forest fruits in southern Xinjiang,the fertilization plan can be adjusted in a timely manner in combination with the processing of walnut powder or walnut milk.