毛白杨幼林节水灌溉效益分析

ANALYSIS OF THE BENEFIT OF WATERSAVING IRRIGATION IN YOUNG PLANTATION OF Populus tomentosa

通过连续８ａ对毛白杨幼林的控水灌溉试验，对灌溉的经济效益及节水效益进行了研究，并对沙地毛白杨幼林的节水灌溉技术进行了分析。结果表明：灌溉不仅促进林木在短期内速生，而且具有长期持续的增产效益；春夏干旱期内灌溉具有很高的经济效益，且随时间的增加不断增长；灌溉的土壤水分阈值和灌溉时期是实现节水灌溉的两项重要指标。在生长季节，特别是林木生长的关键时期，使土壤水分维持在田间持水量的５０％～６０％以上，就可获得较高的经济效益及灌溉水的利用效率。

Through continuous eight years experiments of controlled irrigation in a young plantation of Populus tomentosa, the benefit of watersaving irrigation was studied and the technology for irrigating sand lands was analyzed. The result shows that: Irrigation not only promotes rapid growth in a short period but also improves the longterm production. The economic benefit of irrigation is very high, and it increases gradually with time. The soil moisture threshold and the timing for irrigation are the two important indices for the watersaving irrigation. In the growing season, especially in the critical period for plant growth to maintain the soil moisture over 50%～60% of the field capacity will gain more economic benefit and make better use of the irrigation water.