Effects Of Local Soil Improvement On Apple Growth And Fruit Quality In Mountainous Orchards Of Northern Shaanxi Province

The mountainous area of northern Shaanxi is the dominant producing area of apple,but there are some problems such as environmental pollution,soil compaction and fruit quality decline caused by barren soil,drought and less rain,excessive fertilizer and other factors.In mountainous orchards of northern Shaanxi province,local soil improvement with organic materials and integration of water and fertilizer can effectively improve soil properties,promote root growth,and improve nutrient absorption and utilization efficiency,which is of great significance for promoting green,healthy and sustainable development of apple industry.In this study,the 10-year-old ’Yanfu No.6’/Malus paleng was used as the material,and two groups of six improvement methods and four improvement materials were set up to carry out local soil improvement in mountainous apple orchard,and explore the effects of different improvement methods and materials on soil nutrients,tree body nutrition,fruit quality and yield.The main results are as follows:(1)Local soil improvement was carried out with four acupoint application methods,one acupoint,two acupoints,three acupoints and four acupoints,and two acupoint application methods,single and double.The results showed that soil nutrient content,tree nutrient index,fruit appearance quality,internal quality and yield of various soil local improvement methods were significantly improved compared with CK.Compared with CK,the content of soil organic matter,fresh leaf weight,dry leaf weight,total chlorophyll content and fruit hectare yield increased by 151.83 %,12.8 %,13.7 %,13.38 % and12.40 %,respectively.Compared with CK,the content of soil organic matter,fresh leaf weight,dry leaf weight,total chlorophyll content and fruit yield of hectare increased by148.95 %,20.5 %,17.2 %,14.76 % and 14.00 %.The comprehensive analysis shows that it is better to choose four holes and two strips for local soil improvement of orchard in northern Shaanxi.(2)Four organic materials,sheep dung,grass charcoal,coconut shell and straw,were used to improve the soil of Fuji orchard in northern Shaanxi.The results showed that the improvement of sheep dung could increase the diversity of soil microbial community and significantly improve the body nutrition indexes of fruit trees,among which,the leaf thickness,total chlorophyll content and root activity were both higher than CK,respectively increased by 12.78 %,23.82 % and 40.12 %,the fruit brightness of sheep manure treatment increased by 21.23 % compared with CK,and the yield of fruit hectares increased by12.22 % compared with CK.The difference between the bacterial community and CK was increased by using grass charcoal,and the dry and fresh weight of leaves,total chlorophyll content,net photosynthetic rate of leaves and yield of fruit hectares were significantly increased.The net photosynthetic rate of leaves and yield of fruit hectares were increased by53.74 % and 14.76 %,respectively,compared with CK.Coir improvement is helpful to the diversity of soil microbial community.The maximum number of OTU in soil improvement is 809.Coir improvement can significantly improve dry and fresh leaf mass,total chlorophyll content,root activity,fruit brightness,fruit nutrient content and fruit hectare yield,among which total chlorophyll content and root activity are 23.82% higher than CK.The yield of fruit hectares increased by 18.19 % compared with CK by 80.34 %.Straw improvement could increase the diversity of soil microbial community,and the fresh leaf quality and fruit brightness of fruit trees were significantly improved compared with CK,while the other indicators did not change significantly.The reason may be that straw did not completely decompose in soil,and the improvement effect was less obvious in the current year.The four kinds of improvement materials can be applied to the local improvement of soil of mountain apple orchard in northern Shaanxi.The local improvement of soil with sheep dung,grass charcoal,coconut husk and straw can increase the diversity of soil microbial community,promote the development of fruit tree body,improve the internal and external quality of fruit and increase fruit yield.Local soil improvement with grass charcoal and coir can greatly improve fruit quality,enhance fruit commerciality and increase fruit yield,while local soil improvement with sheep manure can give consideration to both fruit quality and yield.