Nutrient Uptake And Distribution In The Newly Growing Part Of The Shoot In Peach Tree

China is a large fruit producing country,but the research on fruit tree nutrition and fertilization is still inadequate.Fruit farmers have excessively used nitrogen and phosphorus fertilizers in pursuit of output,and excessive and insufficient potassium fertilizer coexist.The backward fertilization method and unreasonable application period lead to a low yield per unit of main fruit trees in China,poor quality,waste of resources and high environmental costs.Therefore,scientific and reasonable nutrient management technology has become an important bottleneck for high-quality and high-yield fruit trees in China.China is the world’s largest peach country,but the current management of excessive and unbalanced application of chemical fertilizers has led to low peach yield,poor quality,and reduced fertilizer utilization.Therefore,it is urgent to improve the nutrient recommended methods of peach orchard.In recent years,Chinese Academy of Agricultural Sciences has proposed and perfected nutrient recommendation methods based on yield response and agronomic efficiency,and achieved yield increase and fertilizer reduce demonstrations on wheat,rice and other field crops.Our research team used multi-year yield response data to initially establish a peach tree nutrient recommendation method(NE)based on yield response and agronomic efficiency,but it lacks the peach nutrient demand parameters based on the QUEFTS model.Therefore,this study initially explored the dry matter accumulation,nitrogen,phosphorus,potassium and other nutrient uptake and distribution characteristics of new parts of peach trees during the fruiting period of peach trees in the main peach production areas of China through different nitrogen treatments and multi-point deficiency experiments.The optimal nutrient requirement of the target yield peach is intended to provide more accurate nutrient requirement parameters for the peach tree nutrient recommendation method based on yield response and agronomic efficiency.The main research results are as follows:(1)The field experiments with minus nitrogen(N),phosphorus(P)or potassium(K)fertilizer showed that the NE recommended fertilization increased the average yield by 11.53 t/ha compared with the farmer’s customary fertilization treatment,while the N,P,and K nutrient inputs of Peach orchards were reduced by 118,38,and 190 kg/ha.Compared with farmer’s customary fertilization,NE fertilization treatment significantly increased the nitrogen content of fruit in 6 peach orchards,an average increase of8.9%;compared with NE treatment,the lack of nitrogen fertilization had a certain effect on fruit nitrogen content,67% of peach orchard fruit nitrogen Compared with the treatment without K fertilizer,NE recommended that the K content of some fruits increased from 24.1g/kg to 38.5g/kg,an average increase of 28.9%.(2)The results of the peach orchard with N level showed that the peach yield increased first and then decreased with the increase of nitrogen application rate.When the N application rate was 372 kg/ha,the yield was the highest,which increased by 44% compared with the no N application.At the same time,the titrable acid content of the fruit at the mature stage was decreased,and the content of reducing sugar,Vc,and soluble solids was increased at the N application rate of 372 kg/ha.In addition,N application rate of372 kg/ha,resulted in the highest biomass,N,phosphorus(P)and K accumulation in newly growing part of peach trees.(3)Through multi-point sampling data analysis,For the dry matter distribution of the newly growing parts,The largest proportion of fruits,,followed by the leaves,and the proportion of fruit reaches 78% on average.Peach leaves had the highest nitrogen content in the leaves of the current year,followed by fruits,and had the lowest nitrogen content in the branches;the N uptake of the newly growing parts was between27.8 and 258.2 kg/ha,with an average of 86.3 kg/ha,and with 61.8% distributing into the fruit.From the point of total amounts,the uptake of K in the new growing part of the peach tree was the highest,followed by N and P.Therefore,the N and K nutrition control of peach trees is the focus of peach nutrient recommendation.(4)The QUEFTS model was used to analyze and evaluate the nutrient uptake characteristics of the newly growing parts of the peach trees,and the optimal nutrient uptake and distribution ratio of N,P and K in the newly growing parts of the peach trees with different target yields were obtained.When the target yield reached the 60% to 70% of potential yield,the nutrient requirements of the newly growing parts by each ton of fresh fruit are nearly same,with values of 2.6、0.25 和 3.3 kg/t FW,respectively.And their corresponding optimal nutrient internal efficiencies are 294 kg/kg N,388 kg/kg N、3947 kg /kg P 和 303kg/kg K,respectively;and the optimal proportion of N,P and K required in fruit are 54.1%、72.9%和75.8%,respectively.