Fertigation Techbology And Potassium Application In Apple Orchard

At present, apple industry has become a pillar industry of the revitalization of agricultureeconomy and increasing peasants’ income in Shaanxi province. However, in recent years, withthe increase of apple production benefit, growers generally attach great importance to thechemical fertilizer input, leading to more nitrogen and phosphorous, less or no K phenomenoncommon in apple orchard. It leads to nutrient supply imbalance, low utilization rate offertilizer, low yield, and poor quality. In this case, the development of apple production isrestricted in Shaanxi province. Confronted with the problems of the excessive nitrogenfertilizer and the lack of potash application in apple orchard, do the two aspects of thisresearch. One is using fertigation in order to seeking the effective ways to improve nutrientuse efficiency, to reduce fertilizer rates. Two is the study of potassium fertilizer application onapple yield and quality in order to seeking the optimal and best potassium fertilizerapplication in apple orchard and to improving quality of the apple. The main conclusions areas follows:1. Response of apple production to fertigation in different types of ecological regionsA field experiment was conducted to investigate effects of NPK traditional, NPKfertigation and1/2NPK fertigaion on the yield, quality and the utilization rate of fertilizer ofapple orchaed in Weibei dry-land and Guangzhong plain. The results show that there areobvious differences of effects of fertigation on apple production, due to the differentecological conditions. On the Weibei dry-land, compared to NPK traditional fertilization,NPK fertigation increased the yield by13.0%, fruit firmness enhanced by10.6%, sugar acidratio increased by19.1%, N, P, K uptake of fruit increased by36.0%,75.3%and44.8%, PFPincreased by14.2%, but when the fertilizer rates be decreased50%, compared with traditionalfertilization, the yield of fertigation was not significantly different, it showed that fertigationcould increase fertilizer use efficiency and reduce fertilizer rates. On the Guanzhong plain,when the fertilizer rates is decreased50%,1/2NPK fertigation increased the yield by26.2%,N, P, K uptake of fruit increased41.8%,98.9%and58.9%, PFP is increased by152.6%.Obviously, using fertigation can reduce fertilizer rates nearly50%in Guangzhong plainorchard, achieving high yield and efficient.2. Effects of potassium fertilizer rates on apple yield and quality In a field experiment, effects of the potassium rates on the yield and quality of Fuji apple.The study concluded5treatments with3replications:0,015,030,0.45and0.60kg K2O/tree.The results showed that increasing fertilizer application could significantly enhance appleproduction, increased by14.9%~14.9%. K application significantly increase apple production,potash agronomy efficiency (AE) and the fertilizer contribution rate (FCR), and the trends areall increased at first and then fluctuated with K application rate increased. When thepotassium rates reach0.30kg K2O/tree, all of them achieve the best results. Potassiumfertilizer had a certain influence on the fruit quality, the content of soluble solids, vitamin C,soluble sugar and sugar acid ratio in apple fruit all conform to the trend of increasing at firstand then decreasing, with the increasing of potassium fertilizer. When potassium was0.30kgK2O/tree, the effect of potassium on quality is best. The application of potassium fertilizer caneffectively increase the weight of100leaves and chlorophyll. With the increasing potassiumrate can enhance the content of K in leaf and fruit, it also promotes the absorption N, P of tree.Between potassium, calcium and magnesium has obvious antagonism. Considering the effectof potassium fertilizer rates on apple production, quality, potassium utilization rate, and thecontent of N, P, K, Ca and Mg in apple leaves and fruit, the optimum potassium fertilizer ratewas0.30kg K2O/tree in apple orchard.3. Effects of varieties of potash fertilizer on apple yield and qualityA field trial was carried out two kinds of Potash (potassium chloride and potassiumsulphate) effects on the apple production. Preliminary evidence of this research, the effects ofusing potassium chloride and potassium sulphate as the potassium supply varieties on appleproduction, quality and agricultural potassium use efficiency (AE) and the fertilizercontribution rate of fertilizer (FCR) is not significantly different. Therefore, choosing chlorideas potassium fertilizer supple is the better benefits than potassium sulphate, because of thecheaper price of chloride. However, from the long-term effect, it still needs further research.4. Effects of application time of potassium fertilizer on apple yield and qualityA field experiment was conducted to study effects of different potassium applicationperiod on the apple production. Results show that the application time of potassium fertilizeris significantly important. Compared with the traditional fertilization habit (100%potassiumbase fertilizer), the treatments of50%base fertilizer application+50%expansion period,50%flowering+50%expansion period and100%expansion period increased the yield significantly,the rate of increase is26.1%、27.6%and20.5%, respectively. At the same time, the fruitweight and excellent fruit rate of these three treatments are all higher. Obviously, applicationpotassium fertilizer in expansion period is crucial to the fruit growth, significantly increasedthe yield of apple. At the same time, the treatment of50%base fertilizer+50%expansion stage increased the single fruit weight, fruit shape index and improved the rate of qualityfruits, and increased the content of sugar, fruit sugar acid ratio and Vc, and reduced thecontent of fruit acid. In terms of leaf and fruit nutrient content, both of50%basefertilizer+50%expansion period and50%flowering+50%expanding period were highernutrient content in leaf and fruit, but the difference was not significant between them. Theresults showed that combined the base fertilizer and topdressing fertilizer has the best effectof potassium fertilization.