Effects Of The Different Time And Methods Of Applying Controlled Release Fertilizer On Apple

Many studies showed that controlled-release fertilizer can improve the nutrient use efficiency of the fertilizers and make the rate of nutrient release accorded with plant nutrient uptake. At present, many studies have reported the effects of controlled-release fertilizer on output, quality and soil environment and so on, but few reports about the technique of application. Taking the full fruit period of “Gala” apple in the Shaanxi province Luochuan northwest A & F university apple station orchard as material, The effect of the applying methods(furrow fertilization, radial fertilization, hole fertilization, broadcast fertilization) and time(fertilizing in autumn only, fertilizing in autumn and summer twice, fertilizing in spring only, fertilizing in spring and summer twice) of controlled-release fertilizer on tree growth and apple quality were studied to promote the scientific application of controlled-release fertilizer. The main findings and conclusions were as follows:1.The applying time experiment showed that fertilizing in autumn only was the best time for the growth of apple tree, the index of the young shoot growth, shutter fresh weigh, shutter dry weight, net photosynthetic rate was significant greater than other treatment. Compared to fertilizing in autumn only(fertilizing in autumn and summer twice), yield per acre of fertilizing in spring and summer twice was increased by 6.98%(10.60%), soluble solids content was increased by9.54%(10.53%), Sugar-acid ratio was increased by 16.83%(14.20%). Considering the cost of labor and other factors, as there was no significant deference between fertilizing in spring only and fertilizing in spring and summer twice, we can apply controlled-release fertilizer in spring.2. The applying methods experiment showed that radial fertilization did best for the growth of apple tree, the index of shutter fresh weigh and shutter dry weight was the highest, while the net photosynthetic rate of broadcast fertilization was the highest. In aspect of yield and quality, the index of radial fertilization and broadcast fertilization was greater than that of furrow fertilization and hole fertilization. Comprehensive consideration the vegetative growth and fruit quality of fruit, radial fertilization is best, broadcast fertilization second, furrow fertilization and hole fertilization is the worst.3. In summary, fertilizing in spring only or in spring and summer twice by using radial fertilization is the best for Apple orchard.