Research On The Production Status Of "Fuping Jianshi" And Establishment Of Recommended Fertilizer Amount

Fuping County in Weinan City,Shaanxi Province is a famous producing area of persimmon.As a local characteristic leading industry,"Fuping Jianshi"industry has effectively promoted the increase of farmers’income and made outstanding contributions to poverty alleviation and rural revitalization in Fuping County.However,in recent years,many problems such as low yield,low fruit quality,low scientific management level and low economic benefit have seriously restricted the sustainable development of persimmon industry.In view of the main problems existing in the fertilization,we take the persimmon-planting area of Zhuangli Town,Caocun Town,Dancun Town,Chengguan Street Office and Donghua Street Office in Fuping County as the research objects,and investigated the cultivation and management status of 92 persimmon orchards.At the same time,8 persimmon demonstration orchards in young and 5 in full fruit orchards were studied.The relationship between fruit yield,quality and soil fertility under different fertilization was analyzed,and the fertilization amount was recommended,The above results can provide a theoretical basis for the establishment of nutrient management scheme of“Fuping Jianshi”.The main results are as follows:1.Our survey of the planting and production of 92 persimmon orchards found that fruit farmers are mainly over 50 years old,with only 4.69%of fruit farmers under 35 years old,generally having a low level of education.The total area of the investigated orchard was 565ha.With the development of persimmon industry,newly planted persimmon gardens are the mainstream,with the planting area accounting for 96%.The planting mode was mainly small area planting,and the orchard with an area of less than 10 mu accounts for 72.83%;the row spacing was mainly 3×4 m and 4×5 m.In terms of fertilization management,58%of fruit farmers adopted the combination of organic and inorganic fertilizers.The base fertilizer was applied after fruit harvest and before germination,and the topdressing was applied at the young-fruitinging stage and fruit expansion stage,and the fertilizer application amount was too high.The organic fertilizer used is mainly commercial organic fertilizer,with an average application rate of 11.36 t/ha.79%farmers applied compound fertilizer.The application period was mainly young-fruitinging period and fruit enlargement period.The average input of N fertilizer in young orchards,early orchards and full fruit orchards was 383,305 and 474 kg/ha,respectively.The average input of P fertilizer was 369,302,405 kg/ha,respectively.The average input of K fertilizer was 247,267 and 385 kg/ha,respectively.In terms of yield,the average yield of the young-fruiting orchard was 18.82 t/ha,and the average yield of the full fruit orchards was 28.73 t/ha.There was a decreasing trend between nutrient input and yield.2.Through the analysis of fruit yield indicators,it was found that the yield of persimmon orchards with high fertilization was 122%higher than that of persimmon orchards with low fertilization.As far as young orchards were concerned,with the increase of fertilizer application,the yield increases first and then decreased.High nutrient input did not increase the NPK content in the fruit,but it could significantly increase the Ca content.The Ca content of the fruit in full fruit orchards with the highest fertilizer application rate was up to 50%higher than that in the persimmon orchard with the lowest application rate.Young orchards showed the same trend.Through the comprehensive evaluation scores of fruit quality in different persimmon orchards,it was found that the fruit quality scores of low fertilization in full fruit orchards and young-fruiting orchards were both higher.3.The soil nutrient status of persimmon orchard under different fertilizer application rates was analyzed,the standard value of soil nutrient content in persimmon orchard in Shaanxi Province was compared,it was found that the soil organic matter content and available potassium content in full fruit orchards were at a too high level,and the available phosphorus content was at a high level.The content of soil organic matter in young orchards was generally at a high level,and the content of available phosphorus and available potassium was currently at a high level.The annual average contents of soil organic matter,available potassium and available phosphorus in high fertilization orchards were significantly higher than those in low fertilization orchards.Through the analysis of soil nutrient content in young orchards with only organic fertilizer application,it was found that applying only 2 t/667m² organic fertilizer per year could make soil fertility at normal level.When 3 t/667m² organic fertilizer was applied,the soil fertility was at the high value level and the yield was the highest.Soil fertility and yield decreased when 4 t/667m² organic fertilizer was applied.The annual application of2～3 t/667m² organic fertilizer can meet the growth needs of young persimmon trees.Correlation analysis showed that the contents of phosphorus,calcium and magnesium in leaves of young orchards were closely related to soil nutrients,and the contents of trace elements in leaves of full fruit orchards were more closely related to soil nutrients content.The contents of soil available phosphorus,available potassium and fruit potassium in young orchard were significantly positively correlated with single fruit weight and vertical diameter,indicating that fertilization had a significant promoting effect on single fruit weight and vertical diameter,while the content of soluble solids concent decreased with the increase of fruit potassium and iron content.There was a significant negative correlation between soil nutrients and fruit soluble solids concent,indicating that excessive nutrient input may reduce fruit quality.4.The results showed that the average N content of persimmon fruit was 3.85 g/kg,the P content was 0.92 g/kg,the K content was 7.40 g/kg,the water content was 80%,and the ratio of N,P and K content was 4:1:8.The amount of fertilizer input is much larger than the amount of fruit absorption during persimmon planting each year.In the case of only considering the amount of fertilizer input and nutrient uptake of persimmon fruit,when the minimum balance coefficients of N,P and K are 6.25,8.01 and 1.23,respectively,it can meet the nutrient demand of persimmon.According to the current average yield of 30 t/ha in full fruit orchards,the recommended application rates of nitrogen fertilizer（N）,phosphorus fertilizer（P₂O₅）and potassium fertilizer（K₂O）in persimmon orchards at different soil fertility levels are 46～77kg/ha,49～146 kg/ha and 109～163 kg/ha respectively..In summary,in the production of“Fuping Jianshi”,it is necessary to strengthen the scientific management and balanced fertilization awareness of farmers.Although high fertilizer input can ensure high yield,it is not conducive to long-term development.Fertilization of persimmon orchards can be targeted based on the recommended fertilization amount in this study.