Study On The Application Effect Of Organic Fertilizer And Chemical Fertilizer In Apple Orchards At Peak Fruit Stage

Luochuan County,Shaanxi Province is an agricultural area featuring apples as the leading industry,and due to its natural geographical resource advantages,it has become a typical location on the world’s best apple breeding belt.However,in the history of Luochuan,natural disasters such as drought,little rain,soil erosion and other natural disasters,coupled with the low soil organic matter content of Luochuan orchards,fruit farmers have long emphasized the application of chemical fertilizers,and soil impoverishment has seriously affected the yield and quality of apples,and even caused great harm to the soil environment,becoming an obstructive factor in the development of Luochuan apple industry.Based on the importance of fertilization to apple production and the current situation and impact of fertilization in orchards,this study set up two different groups of fertilization schemes for organic fertilizer increase and chemical fertilizer reduction in Jiuxian County,Luochuan County,Shaanxi Province,taking the Fuji variety Qiaohua’Changfu 2’as the test material,combined with the characteristics of long-term organic fertilizer and chemical fertilizer fast-acting,and studied the effects of different fertilization levels on soil fertility,fruit tree growth,fruit quality and yield through a two-year field experiment.In order to explore the scientific fertilization ratio suitable for apple production at peak fruit stage,the main results are as follows:1.Effects of organic fertilizer application on growth,quality yield and soil fertility of‘Changfu 2’apple.Compared with single application of chemical fertilizer(M0),the soil nutrient content of the cultivated layer could be increased to different degrees,with an increase of 5 kg/plant(M1),10 kg/plant(M2),15 kg/plant(M3),and 20 kg/plant(M4)in organic fertilizer.In a certain range,it can also improve the leaf thickness,shutter weight,leaf area,SPAD value and net photosynthetic rate,and the M2 treatment effect is the best.The contents of vitamin C,nitrogen,phosphorus and calcium in apple treated with M2 and M3 were significantly higher than those in M0 treatment,and the potassium content of pulp in M2 treatment was the largest.Compared with the control M0,the weight of single fruit,peel hardness,pulp crispness and solid-acid ratio reached the maximum value,which increased by 11.7%,3.3%,1.63%and 6.51%,respectively.The red saturation a*of M3-treated fruits was better,and the brightness L*and color saturation CI of M2-treated fruits were the highest.Compared with the control M0,the M2-treated fruits had the most obvious increases in commodity rate,yield and income added value.Based on the performance of various indicators,it is most suitable to add 10 kg/plant(M2)of organic fertilizer in the actual production of orchards.2.Effects of topdressing and chemical fertilizer reduction on growth and development,quality yield and soil fertility of‘Changfu 2’apple.Compared with 100%chemical fertilizer(CK),the soil organic matter content treated with 90%chemical fertilizer(T1),80%chemical fertilizer(T2)and 70%chemical fertilizer(T3)increased,and the soil nitrogen,phosphorus and potassium nutrient content decreased slightly with the reduction of fertilizer application in each topdressing period.The net photosynthetic rate of T2 treated leaves reached the maximum value,which was increased by20.21%compared with CK treatment.With the advancement of phenological period,the nitrogen,phosphorus and potassium contents of leaves treated with reduced fertilizer treatment showed an overall downward trend,while the calcium content of leaves showed an upward trend,and the magnesium content of leaves was the highest in the fruit expansion stage,and then decreased,and the calcium and magnesium contents of leaves performed optimally in T2treatment.The weight of the single fruit treated with T2 and T3 was large,but the fruit shape index of T2 treatment was the highest,and the fruit shape was more comprehensive.The yellow saturation b*treated with T2 and T3 was lower,but the red saturation a*and color saturation CI of T2 treatment were higher than those treated with T3,and the peel coloring effect was the best.Compared with the control CK,the skin hardness,pulp crispiness,solid-acid ratio and apple vitamin C content of T2 treatment increased by 16.36%,9.6%,12.66%and 9.26%,respectively.When the chemical fertilizer is reduced by 20%～30%,the yield of the orchard is reduced,and the yield of T2 and T3 treatment is 0.05%and 0.14%respectively compared with the CK treatment,but the highest commercial fruit rate of T2 treatment is86.67%,and the added value of income reaches 18,700 yuan/hm~2,and the income of T3treatment shows negative growth,reducing the income by 20,200 yuan/hm~2.Comprehensively considering the input and output elements of the orchard,it is concluded that reducing the application of chemical fertilizer by 20%during top dressing can improve the quality and efficiency of the orchard.Under the conditions of this experiment,the most suitable fertilization scheme for red Fuji apple orchards at peak fruit stage was 10 kg/plant of base fertilizer,organic fertilizer+top dressing and 20%chemical fertilizer.