凉城县多年来的实践证明,用良种杨树大苗植树造林有许多优越之处。据典型测算的数据表明,用良种杨树大苗植树造林成活率高,比栽植老枝条或幼苗的成活率提高24.7%,一般可达90%左右。且成材快,经济效益高,水分好的地方4年可成椽,每株可收入3元,10年可成檩,每株可收入30 The practice in Liangcheng County has proved for many years that there are many advantages to using afforestation with seedling poplar seedlings. According to the typical measured data show that seedling afforested with good seedling high survival rate, than the old branches or seedlings planted survival rate increased by 24.7%, generally up to 90%. And become fast, high economic efficiency, good water 4 years into rafters, each plant income of 3 yuan, 10 years into Cheng, each plant income 30