Study On Seasonal Variation Of The Amounts Of Nutrients In ’Youhou’ Sweet Persimmon And Orchard Soil And Balanced Fertilization Design

At present,China’s sweet persimmon in its suitable planting area has formed a development boom,but the production is generally adopted in the traditional cultivation and management,production is unstable,quality in general and economic efficiency is not high.Based on the analysis of the soil nutrient status of the National Field Genebank for Persimmon of China and demonstration garden of sweet persimmon,this experiment hopes to provide a test basis for the establishment of an efficient fertilization management model of ’Youhou’ sweet persimmon.The main results are as follows:the trend of nitrogen change is increased-decreased,peaked at flowering stage,and the change of phosphorus content in leaves is similar.Changes in potassium content fluctuate more,will peak in mid-September.Calcium changes in the trend to reduce-increase,will appear in the first half of May the lowest value.Magnesium content has gradually increased.The zinc content fluctuates slightly after the flowering stage drops to a low level.Iron content no significant changes in the young fruit will appear a smaller peak.Manganese content has gradually increased.Soil organic matter content has two reduction process,once in late April and one is in late May to mid-September.The contents of nitrogen,phosphorus,potassium and calcium in high yield tree(’ Youhou’ sweet persimmon in the National Field Genebank for Persimmon of China)were higher than those in low yield tree(’Youhou’ sweet persimmon in demonstration garden of sweet persimmon).However,the content of micronutrients elements in zinc and magnesium of high-yielding trees is lower than that of low-yield trees.The two levels of iron and manganese are basically the same.Indicating that the lack of nitrogen,phosphorus,potassium,calcium is one of the major limiting factors leading to low yield.Fertilization throughout the year can be divided into three periods,leaf stage to flowering period,young fruit period to coloring period and after fruit ripening.There were differences in the types and quantities of fertilizers applied during each period.The three fertilization period,nitrogen fertilizer,phosphate fertilizer,potash fertilizer,calcium fertilizer,magnesium fertilizer,mineral element fertilizer application ratio is about 100:15:33:42:4:2,30:4:27:29:3:2,42:7:25:87:3:2.