Abstract:

The study on the change law in N, P, K contents of early spring Salix matsudana Koidz branches is to judge the quality of nutritional status of dormant buds in germination. The experiment takes Salix matsudana Koidz 1-4 year-old branches as materials to study the change in water content and N, P, K content of branches from April 1 to 28. The results showed that: the water content of 1-3 year old branches increased significantly with time, the average rate of increase being more than 29% while that of 4-year-old branches was stable, the rate of increase being only 2.93%; the nitrogen content of branches increased at first and then decreased; the nitrogen contents differed greatly among branches of varied ages prior to April 21 while there was a slight difference in nitrogen content among 2-4 year-old branches before the 28th, which was lower than that of 1-year-old branches. The Phosphorus content differed significantly among the 4 treatments from the 1st to the 7th while that of 2-4 year-old branches differed slightly; On April 1, the potassium content among different treatments differed significantly. And they changed greatly and less regularly in the later stage. Comprehensive analysis showed that the water content and N,P,K content of branches increased with the strengthening life activities of trees, but the foliar P and K content decreased significantly after germination.