黄 土 丘 陵 区 穴 衬 膜 造 林 技 术

穴衬膜栽植技术是指树木栽植时，在挖好的栽树坑底部和四周衬贴一层防渗薄膜（厚度为0.000 7 mm可降解塑料薄膜），树木栽好覆土浇水后，再在地表面覆膜，防止栽树浇水(施肥)的渗漏和蒸发，使树根在栽植后较长时间内处于含水量较高、四周封闭的潮湿土壤之中，从而达到提高成活率和促进林木前期生长的目的. 1997—2001年，作者在延安市宝塔区枣园镇下砭沟小流域采用田间对比试验法进行了5 a试验.结果表明，该技术可有效防止树根周围土壤水分和养分的蒸发与渗漏，促进浅层根系的生长发育，保水作用可持续4个月以上，对各种树木成活率和生长量均有显著促进作用，在黄土丘陵地区可提高林木成活率31-5%，年均枝条生长量提高57%，在人工造林中具有广阔的推广前景. 

Effects of "cave padded plastic film" afforestation technique in Loess hilly-gully regions

A new afforestation technique, “cave padded plastic film”, was proposed which was designed for forestation in Loess hilly_gully areas. The design of this technique is to dig a soil pit before planting, padding plastic film (the thickness of the film is 0.000 7 mm, decomposable) around the wall and on the bottom of the soil cave; then planting, filling with soil and covered with film to avoid leakage and evaporation, making a closed and wet environment suitable for plant growth. From 1997 to 2001, the authors made many tests in Xiabian Valley, Zaoyuan Town, Baota District of Yan’an City, West China’s Shaanxi Province, to test the effects of this new technique, compared with traditional ways. The results show that the cave padded plastic film" afforestation technique can prevent evaporation of soil moisture and leakage of soil nutrition and remarkably improve the survival rate and growth of artificial afforestation, and this situation can last for more than 4 months. The survival rate can increase by 31-5% and the biomass of branches by 57%.