缓释肥加载对浙江楠和闽楠容器苗生长和养分库构建的影响

Effects of Slow-Release Fertilizer Loading on Growth and Construction of Nutrients Reserves of Phoebe chekiangensis and Phoebe bournei Container Seedlings

采用单因素完全随机区组设计,以珍贵阔叶树种浙江楠和闽楠为材料,对不同缓释肥施肥量下的1年生轻基质容器苗生长性状和氮磷养分吸收情况进行测定分析,系统研究缓释肥加载对容器苗生长和养分库构建的影响。结果表明:当施肥量为3.0 kg·m-3时,2种楠木容器苗的苗高生长量达最大值,同时具有最大整株干质量;根系发育和根冠比则在1.5 kg·m-3施肥量时表现较好。缓释肥的加载有助于提高养分库的氮含量和浓度,3.0 kg·m-3施肥量时实现氮养分库的最大积累量。缓释肥施肥水平的提高对磷含量的提升不显著,且对磷浓度产生一定抑制作用,故认为1.5 kg·m-3的施肥量已满足磷养分库构建的磷素需求。相关分析发现,氮磷养分含量与苗高、地径及根系生长量呈显著正相关,养分浓度则主要与根冠比相关,提高氮磷养分含量可有效促进苗木的生长发育。3.0 kg·m-3施肥量可实现浙江楠和闽楠氮磷养分库的构建,并获得较高的生物量,符合高品质容器苗培育的要求。本研究容器苗磷素供给表现过量的现象,可通过选择低磷缓释肥或结合其他施肥技术来解决。分析换算得出,1年生浙江楠和闽楠容器苗最佳氮肥施肥量分别为420 mg·株-1和360 mg·株-1,最佳磷肥施肥量均为60 mg·株-1。

A univariate completely randomized block design was applied in this experiment. Growth traits, and the nitrogen （N） and phosphorus （P） uptake of Phoebe chekiangensis and Phoebe bournei under different levels of slow-release fertilizer （SRF） were measured to investigate the effect of SRF loading on seedling growth and construction of nutrients reserves. The result showed that the largest plant height, root volume and dry weight of the two Phoebe species were detected with 3.0 kg · m-3 SRF treatment. SRF loading increased N content and concentration of nutrients reserves, and the largest nutrients reserves was constructed at 3.0 kg · m -3 SRF. P content of seedlings was not changed by increasing SRF applications, whereas the P concentration was decreased by SRF application. Thus, 1.5 kg · m-3 SRF would be enough to provide P for constructions of nutrients reserves. Correlation analysis revealed there was a positive correlation between the N and P content and plant height, basal diameter and root growth, and a positive correlation between the N and P concentration and root-shoot ratio of seedlings. It was effective to promote seedling growth by raising the N and P content. The 3.0 kg ~ m-3 SRF might meet the requirement of high quality seedlings, and with the SRF, N and P nutrients reserves could be constructed and higher biomass was able to be obtained. By choosing SRF with low-P content, or applying other fertilization technology, the problem of excess supply of P might be solved. It was demonstrated that the optimum fertilizing amount of N of Ph. ehekiangensis and Ph. bournei would be 420 mg per plant and 360 mg per plant, respectively, while the optimum fertilizing amount of P for the two Phoebe species would be 60 mg per plant.