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

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.