贺兰县位于中温带干旱半荒漠区,属大陆性气候,以往造林均在春季,但早春土壤解冻慢,化冻浅,植树过早时土层冻结,起苗难,伤根多,挖定植穴费工费时,栽植浅成活率低;植树过晚则苗木发芽,养分消耗,树坑跑墒;加之农事繁忙,劳力紧张,季节稍纵即逝,适宜时间只有10天左右。贺兰县在七十年代中期大搞四旁绿化时,曾在红星、光明等地进行过小型的秋季植树试验,近期又在县林场,金山草原试验站等地先后进行过秋季林网建设,有成功的,也有失败的。所栽杨树苗木往往枯梢抽干严重,加之量小面窄,基层干部和农民群众难以接 Helan County is located in the temperate arid semi-desert zone, belongs to the continental climate, the past afforestation is in the spring, but the early spring soil thaw slow, shallow thawing, soil premature soil freezing, seedling hard, root injury, digging planting hole Time-consuming forage, planted shallow survival rate is low; planted trees are too late seedling sprouting, nutrient consumption, pit run moisture; coupled with agricultural busy, labor-intensive, the season fleeting, suitable time is only 10 days or so. Helan County in the mid-seventies vigorously engage in greening around, had Red Star, Bright and other places conducted a small autumn tree planting test, and recently in the county forest farm, Jinshan Prairie pilot station and other places have been carried out in autumn forest network construction, there Successful, there are also failed. The planted poplar seedlings are often drained dry serious, combined with a small amount of small surface, grassroots cadres and peasants difficult to access