The Dynamic Changes Of Carya Cathayensis Sarg. Nutrients

This dissertation studies on changes of mineral elements and nutrients during hickory growth and development,including the dynamic changes of N,P,K,Ca and Mg in hickory male flowers,leaves, nuts and soil and the accumulation and transformation of crude protein,Soluble sugar and crude fat in nuts.The results were showed as follows.1.The mineral elements display the different tendencies from April to September.The concentrations of N,P,K elements continually decrease,the rate of decrease is fastest in April and May,lowest in June and July.On the contrary,the concentrations of Ca,Mg elements continually increase,the rate of increase is fastest in April and May,lowest in June and July.During June and July,the concentrations of mineral elements change more slowly,it's best time to pick the leaves samples for leaf diagnosis.2.A male inflorescence has 8.981mg N,0.333mg P,6.114mg K,1.138mg Ca,0.646mg Mg. Its growth and development consumes a great of water and nutrition.To emasculation in spring is effective to improve the hickory's yield and quality.Earlier is better.3.In addition to P,nut absorb nutrition from the outside is less than 15 percent after the August 5^th.They are re-distributed between kernel and shell.N,P,Ca and Mg are transferred from the shell to kernel.On the contrary,K element is transferred from the kernel to shell,which concentration is six times kernel's.To extract potash from the shell is effective and feasible and it can reduce pollution, costs and increase farmers' income.4.The crude protein and soluble sugar contents reduce the bottom until harvest.It's reasonable to harvest nut when it's vitality and transformation is weak.After harvesting the P and K flow to the leaves and the content of fat is rising stage this time.We know that the kernel is still in filling when we harvest.To defer a certain period of time to harvest will improve the quality of hickory.5.To provide adequate N,P,K fertilizer before shell hardening is very important.This time the nut weight achieves 75 percent more a complete nut,the concentrations of N,P,K in soil reduce the bottom.If the concentration of N,P,K less than normal level,it will cause more serious damage. When kernel filling in August,P element has a strong absorption.The accumulation between P and fat has a significant correlation(r=0.9881＞r_0.001,4=0.9741).To provide more P fertilizer maybe improve crude fat content and quality.