容器规格和养分加载对珍贵树种容器苗生长的影响

容器规格和养分加载量是影响容器苗生长的关键因素。以红豆树、浙江楠、浙江樟和赤皮青冈的2a生容器苗为对象,设置容器规格和缓释肥加载量2因素4水平的析因试验,分析不同容器规格、缓释肥加载量及其交互作用对各珍贵树种生长的影响,筛选适宜的容器规格及缓释肥加载量。结果表明,随容器规格和缓释肥加载量增大,各树种容器苗生长势愈好,容器规格为C3(18cm×20cm)时,各树种容器苗苗高、地径和生物量最大,容器规格增大到C4(20cm×20cm),仅赤皮青冈苗高有显著提高;而容器苗生长量较大时对应的加载量则因树种而不同,红豆树和赤皮青冈为F2(2kg·m^-3),而浙江楠和浙江樟则为F3(3kg·m^-3)。根系生长量亦随容器规格变大而增加,红豆树、浙江楠、浙江樟和赤皮青冈根系分别在容器规格C3、C2(16cm×18cm)、C4和C4时发育较好;红豆树根系随加载量增加变细变长,其根系体积在加载量F2时最大,浙江楠和浙江樟分别在加载量F3和F1时根系各项指标值较大,加载量增加反而抑制浙江樟根系生长,赤皮青冈根系则受加载量的影响不明显。各树种根冠比随容器规格增加变化不大,但随着加载量的增加,均表现出减小的趋势,最小加载量F1(1kg·m^-3)时,根冠比最大。除红豆树外,容器规格和加载量2因素对各树种的交互效应明显,经初步评价,红豆树、浙江楠、浙江樟和赤皮青冈优质容器苗培育的组合分别为C3F2、C3F3、C3F3和C4F2,相对其他3树种,赤皮青冈更适宜于较大规格的容器;浙江楠和浙江樟较红豆树和赤皮青冈要求更多的基质养分。

Effects of Container Size and Nutrition Loading on the Seedling Growth of Precious Tree Species

Container size (CS) and slow-release fertilizer (SRF) loading were the key factors affecting the growth of container seedlings.In this study,2- year-old container seedlings of 4 key precious tree species in southern China were used as research objects,including Ormosia hosiei,Phoebe chekiangensis,Cinnamomum japonicum and Cyclobalanopsis gilva .A factorial test with 2 factors and 4 levels of CS and SRF loading was carried out.The effects of different CS,SRF loading and their interactions on the growth of 4 precious tree species were analyzed.And the suitable CS and SRF loading for the growth of the container seedlings were selected.The results showed that with the increase of CS and SRF loading,the growth of the container seedlings becoming better.When the CS was C3 (18 cm×20 cm),the seedling height,the root collar diameter and the biomass were the largest,with the CS increased to C4 (20 cm×20 cm),and the height of the seedlings increased significantly only for C.gilva .While the suitable SRF loading was different with varied tree species.The better SRF loading dose for O.hosiei and C.gilva was F2 (2 kg·m^-3 ),and that for P.chekiangensis and C.japonicum was F3 (3 kg·m^-3 ).The root growth also increased with the CS,and the roots of O.hosiei,P.chekiangensis,C.japonicum and C.gilva were better developed in C3,C2 (16 cm×18 cm),C4 and C4,respectively.And the root of O.hosiei was thinner and longer with the increase of SRF loading,the root volume was the largest with loading dose of F2.While,the larger root index values of P.chekiangensis and C.japonicum were at the loading dose of F3 and F1,respectively.And the root growth of C.japonicum was inhibited by the increasing loading,but C.gilva was not.The root to shoot ratio of each tree species changed little with the increase of CS,decreased with the added loading dose.The root to shoot ratio was the largest with the minimum loading of F1 (1 kg·m^-3 ).Except for O.hosiei ,the interaction effect of CS and SRF loading on the growth of the seedlings was obvious.After preliminary evaluation,the optimal combinations for the seedling growth of O.hosiei,P.chekiangensis,C.japonicum and C.gilva cultivations were C3F2,C3F3,C3F3 and C4F2 respectively,which indicating that relative to the other 3 species, C.gilva was more suitable for larger size containers,while P.chekiangensis and C.japonicum required more nutrients than O.hosiei and C.gilva .