切根和施肥对银杏大苗生长的影响

Effect of Root Cutting and Fertilization on Growth of Ginkgo biloba Saplings

为探讨切根和施肥对银杏Ginkgobiloba裸根大苗生长的影响,同时为了缩短移栽后的缓苗期,2013-2014年在浙江省长兴县选取了15年生实生银杏裸根苗24株,2015-2017年选取了5~10年生实生银杏裸根苗72株,分别进行了两次切根和施肥试验,第一次的试验结果表明:一次切掉1/2的侧根,对苗木胸径、树高生长无明显影响,切根一年后侧根上细根数量大幅增加。第二次的试验结果表明:切根处理的苗木胸径、树高增长量均低于对照CK的增长量,但差异不显著,说明切根对银杏裸根苗的生长有所抑制,但影响不大;在不切根时,施肥对苗木树高的促进作用较为显著,同时切根与开沟施肥时,对银杏树高和胸径生长均有一定的抑制作用。两因素(切根与施肥)的主效应和交互效应分析显示,对于树高生长,切根与否不是影响树高生长的主要因素,施肥才是;对于胸径生长,则恰好相反;不管是对树高生长还是胸径生长,两因素间均存在交互作用,同时也表明分期切根和开沟施肥可作为实用技术推广到生产实践中。

Two experiments were conducted on root cutting and fertilization on growth of Ginkgo biloba saplings in Changxing, Zhejiang province. 15-year bare-rooted G. biloba saplings(the first experiment) were selected for root cutting and application of compound fertilizer in December, 2013. 5-15-year bare-rooted G. biloba saplings(the second experiment) were selected for root cutting in December, 2015 and in January, 2017 and application of organic or compound fertilizer. Determination of height, DBH and fine root were implemented before and 1 year after treatment. The first experiment showed that cutting of one and half lateral root had no evident effect on height and DBH growth, but fibrous roots increased 1 year later. The second treatment demonstrated that height and DBH growth of saplings with root cutting was smaller than that of the control(no root cutting and no fertilization), but no significant difference among them. Main and interact effect analysis resulted that fertilization was the main effect of sapling height growth, while root cutting was the main one of DBH. There were interactions between height and DBH increment.