论文部分内容阅读
在我国造林实践中很早就有深栽的经验.七十年代初期,法、意等国开始研究杨树深栽插干造林技术,取得了好的效果.河北林专和沙河林管局于1980年3月在保定地区西陵和沙河林管局东分场进行了深度50,100、150、20。厘米挖穴栽植。沙兰杨和意大利一214栽深100~一200厘米;自榆栽深50一150厘米。试验效果;前者(两种杨)高生长为对照(50厘米)2.5一 6.7倍,胸高断面积生一沃为对照的1.6一3.8倍,材积生长为对照的1.6一2.7倍,平均全木于物质积累为对照的1.1一3,2倍,根系密集层在。一50厘和150厘米。其侧很增长量为对照的1.5一5.5倍;白榆深栽从高生
In the early 1970s, France, Italy and other countries began to study the deep planting and planting of poplar afforestation technology and achieved good results. Hebei Forestry College and Shahe Forestry Authority in 1980 In March, a depth of 50,100,150,20 was conducted in Xiling, Baoding Prefecture and east of Shahe Forestry Bureau. Cm digging hole planting. Sallam Yang and Italy 214 planted 100 to 200 cm deep; from Elm planting depth 50 to 150 cm. The results showed that the former (two kinds of poplar) grew 2.5 to 6.7 times higher than the control (50 cm), 1.6 to 3.8 times as much as the control and 1.6 to 2.7 times the volume to the control Material accumulation of 1.1 to 3 times as much as the control, root dense in. A 50% and 150 cm. The side of the growth rate of 1.5 to 5.5 times the control; elm planted from high students