Effect Of Compositions Of Substrate And Ratios And Level Of SRF On Qualities Of Seedling Growth Of Phoebes

Phoebe chekiangensis and Phoebe bournei were the valuable timber tree species which had been focus on developing in mid-east region of China. But the development scale was restricted by lacking of germplasm resources and slow growth rate. This problem could be solved by cultivating high-quality container. In order to achieve the goal, we could adjust the combinations and ratios of substrate and the level of slow-release fertilizer (SRF) to improve growth and construction of nutrients reserves of containers. It is study on the substrate and SRF in cultivating of P. chekiangensis and P. bournei in this paper. In order to disclose the effect of combinations and ratios of substrate and their interaction on seedling growth and root development of1-year Phoebes, the mixtures of peat, perlite, husk of rice, powdered bark and peat-mushroom scrap were regard as substrates, and to disclose effect of SRF loading on seedling growth and construction of nutrients reserves, another1-year Phoebes with different level of SRF were tested on their growth traits and N/P nutrient uptake. Otherwise, a factorial experiment was designed to disclose effects of ratios of substrate and level of SRF on growth and construction of nutrients reserves of2-years P.chekiangensis.The results indicated that:1. Phoebe seedlings exhibited better growth performance under compositions of substrate of peat-perlite, peat-husk of rice and peak-powdered bark grew than that of peat-mushroom scrap. Seedlings exhibited the largest height and basal diameter when proportion of peat was70%, whereas root developed best when proportion of peat was50%. There were significant effects of compositions of substrate xratios of substrate interaction on seedling growth, and significant differences in growth traits were detected among different groups of compositions of substrate x ratios of substrate. The ratio of7:3for peat:husk of rice/powdered bark and8:2for peat:husk of rice/powdered bark were demonstrated as most appropriate ratios for P. chekiangensis and P. bournei respectively.2. The largest plant height and dry weight of Phoebes were detected at3.0kg-m-3SRF. SRF loading contributed to improve N content and concentration of nutrients reserves, and the largest nutrients reserves was constructed at3.0kg·m-3SRF. P content of seedlings was not improved by increasing SRF applications, whereas P concentration was decreased by SRF application. Therefore,1.5kg·m-3SRF was deemed to can provide enough P for constructions of nutrients reserves. It was demonstrated that the optimum fertilizing concentration of N of Phoebe chekiangensis and Phoebe bournei are420mg per plant and360mg per plant respectively, while the optimum fertilizing concentration of P for both of the two Phoebes is60mg per plant.3. Ratios of substrate had only effected on height of containers. The containers grew higher when the content of peat was45%than it was35%. The level of SRF affect construction of nutrients reserves of2-years P. chekiangensis more significantly than ratios of substrate. Higher-level of SRF is benefit of development N content and concentration. On the contrary, lower-level is benefit of development P content and concentration. It was demonstrated that the optimum fertilizing concentration of N of2-years Phoebe chekiangensis is more than8.4g per plant and the optimum fertilizing concentration of P is less than1.2g per plant. In order to provide enough N, topdressing could be taken in the growth of2-years containers.