| Seedlings with nutrition loaded performance well in recovering, growth and competition during early period after transplanted compared with that of common ones. Considering the key technical point-nutrition loading in container seedling cultivation for precious species in the south of China, this topic would keep focus on, Phoebe chekiangensis, Cinnamomum chekiangense, Taxus wallichiana var. mairei, Cyclobalanopsis gilva, and Schima superba which are five important species in south province of China. Different levels of control-release fertilizer with varied ratio of N:P would be applied to the container seedlings of these species following factorial experiment design. According to the theory of ecological stoichiometry, the variation of plant growth and nutrition absorption which along with nutrition content and ratio of N:P changes in stroma would be analyzed, and the characteristics of internal stability of the tree species would be cleared. Construct allometric relationship between plant growth and nutrition content of the trees during growth period. Set the suitable amount of nutrition and N: P ratio that meets nutrition loading of the plants. The main results were as follow:(1) Different types of controlled-release fertilizer(CRF) did not show significant effects on the growth rhythm of the precious tree species. While, the precious tree height growth rhythm displayed different:Ph. chekiangensis entered into the fast growing period lately, and the overtime of its fast-growing period was also later compared with other species; However, C. chekiangense was on the contrary, the rapid growth stage not only started earlier but also ends earlier; While, T. wallichiana var. maire stared fast-growing stage earlier, but ended later, so the growth curve was gentle; The fast growing period of C. gilva turned 10 days in advance compared to Ph. chekiangemis,S. superba belongs to fast-growing tree species but it entered into the fast growing period relatively late, while the overtime was relatively early, so its high growth curve is more close to the fast-growing species "S" curve.As a result, the management of water and fertilizer for the container seedlings should fellow their growth rhythm. It should provide water and fertilizer for the rees timely.(2) The suitable nutrition proportion and level for the precious tree species were ditterent: Ph. chekiangensis likes N more compared to other kinds of tree, it needs relatively high proportion of N and high dose of CRF, recommended by N:P being more than 2.25:1, and the does of CRF amount per cubic matrix should not be less than 3.5 kg;The ratio of N:P is relatively low both for T. wallichianavar, mairei and S. superba, but the does of CRF the two need are relatively high. High dose added for them can achieve better growth effect, CRF adding quantity should not be less than 4 kg per cubic subtrate;The sutibale ratio of N:P in CRF for C. gilva is 3.25:land the does of CRF per cubic matrix added was 4.5 kg. Which indicated the tree is the type of N needing;C. chekiangense is the lowest nutrient requirement among the 5 tree species. It did not show obvious nutrient especially N demand. The N:P ratio and does of CRF per cubic substrate in 1.75:1 and 1.5 kg individually is able to meet its growth needs.(3)The N:P ratio and levels for nutrition loading of the tree species diaplayed varied:The nutrition proportion did not present obvious effect like the level of CRF on nutrition loading for the tree growth. And the level of nutrition loading for the five tree species were all 3.5 kg fertilizer added in every cubic substrate. While, the ratio of N to P of the nutrition loading for the tree species were different:The ratio of N:P that make Ph. chekiangensis achieve N and P loading should be higher than 2.25:1;While the suitable N:P for T. wallichiana var. mairei reaching N loading should be higher than or equal to 2.25:1, but the ratio for it’s P effective loading should be smaller than or equal to 2.25:1;The N:P ratio for N and P effective loading both for C. gilva and S. superba were 1.75:1 and 2.25:1 repectively;N and P effective loading for C. chekiangense affected by N:P. For the setting ratio in the research the suitable N:P of CRF for it’s effective oading should be less than 2.75:1... |
