栽植杨树大苗具有成林成材早、易于管护等特点,因而很受群众喜爱。从七十年代开始,呼市地区采用杨树大苗造林的比重越来越大。但目前苗圃培育的杨树大苗,多数是插条育苗、留床培育。育苗密度大,长期留床,土壤肥力衰退,苗木质量存在严重问题,影响造林成活。表现在如下几个方面: 一、苗木根系发育不良, Poplar seedlings planted with forest timber early, easy to care and other characteristics, which are popular with the masses. Since the seventies, the proportion of poplar seedlings afforestation has been increasing in Hohhot. However, nursery poplar seedlings nurtured the majority of the cuttings nursery, leaving bed nurturing. Nursery density, long-term stay bed, soil fertility decline, seedling quality problems, affecting afforestation survival. Performance in the following areas: First, seedling root system dysplasia,