摘要
干旱地区杨树灌溉造林可以防风护田、生物排水、提供木材和其他林副产品、改善人类的生态环境,具有重要的意义。干旱地区水分不足,通过灌溉可以发展杨树,但必须开源节流,合理用水,做到水土平衡。沿渠带状造林省水省地省工,林木生长好,效益高,应作为主攻方向,水土条件好的地方可以发展杨树片林,此外,胡杨的引洪灌溉造林和盐碱地造林也很有发展前途。当前干旱地区杨树灌溉造林的水平不高,生长量低,还有相当大的潜力,除管好现有林木,促进生长,提高质量外,今后发展中必须注意克服以往造林中选地和造林技术不当、树种单纯、造林过密、管理粗放、灌水不足、牲畜及病虫危害等问题。本文在调查研究和田间试验的基础上,结合有关资料,对干旱地区杨树灌溉造林中的一些问题进行初步的探讨。
Afforestation of poplar in arid zones by irrigation can protect farmland and prevent windburn as well as drain off ground water by transpiration of trees which can avoid the soil secondary saline-alkalizing, provide timber and benefit the terms of ecology. Arid zones are perpetually short of water, so developing poplar forest must increase income and decrease expenditure of water, utilize it resaonably, accomplish balance between water and land. Planting poplar belted along the sides of irrigation ditch where if there is non-protection against seepage. This side, especilly the inside slope of irrigation ditch has enough soil water for trees to grow without special irrigation, using manpower, earth and water sparingly. Therefore, this sites are the major places for poplar's afforestation in arid-irrigated farmlands which have great potentialities. Afforestation of poplar by irrigation at some stretched lands which abounded with water and earth resources are also an important way in arid zones. Euphrates poplar(populus euphratica ) is a major species at saline and alkaline soil in arid zones where it occupies a major place. At summer draw the rich flood to the natural forest to promote it regeneration and growth by natural seeding, sprouting and rejuvenation. At present,owing to the afforested site unsuitable, planted too close, managed extensively, harmed by diseases and insect or stocks, especially irrigated insufficiently, the forest of poplar is relatively poor in many arid zones. In future, these problems must be surmounted so that can be developed more well and quickly.
