天山北坡农田防护林合理灌溉量研究

STUDY ON PROPER IRRIGATING QUOTA OF SHELTER-FORESTS ON THE NORTHERN SLOPE OF THE TIANSHAN MOUNTAIN

本文对天山北坡箭杆杨成林农田防护林带进行了灌溉量试验研究。根据试验结果计算出其净灌溉需水量，确定了本区域新的灌溉制度并对农田防护林建设的发展方向进行了论述。

The experiments of irrigation quota were carried out in the mature shelterbelts of Populus nigra. The results demonstrate that the water consumption is increased with the increase of irrigation, the irrigation quota of 60mm can keep the growth of timber close to that of irrigation quota of 150mm, and can permeate through a soil layer of 3m thick on the basis of a series irrigation. Accordingly, the net annual amount of irrigation is 636.96mm.In the new irrigation system of shallow and diligent irrigation, the irrigation quota of shelterbelts on the northern slope of the Tianshan Mountains is 60mm (600m3/ha) eachtime and once a month from April to November except twice a month from June to August. In the viewpoint above, the annual irrigation times and quota are 11 times and 660mm respectively. According to the actual amount of surface water resources in the area,the new irrigation system is improved as a scientific basis for the forest coverage to be up to 13.8%. Meanwhile, some measures are presented for adopting the new irrigation system and proper cultivation system and improving the structure of shelterbelts so as to achieve a compound ecosystem of agriculture and forestry and save water resources.