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毛白杨是华北平原地区主要造林绿化树种之一。一些苗圃由于条件所限,经营粗放,特别是灌溉条件难以保证,苗木质量达不到要求,等外苗数量增加,出现成片“小老苗”。这种苗木不仅不能按计划出圃,影响了经济收益,而且也影响了造林绿化速度。针对这一问题,我们曾于1980年采用平茬、截梢两种措施进行了试验。当年秋后调查,截梢比平茬效果好,平均苗高和地径分别比平茬苗多65厘米和0.28厘米,而且减少了因平茬而造成上年度的干物质浪费和地力消耗。为此,1981年对截梢强度问题进行了研究,现将结果整理如下,供生产和研究单位参考。
Populus tomentosa is one of the main afforestation species in the North China Plain. Some nurseries due to conditions, extensive operation, especially difficult to guarantee irrigation conditions, seedling quality does not meet the requirements, such as the increase in the number of external seedlings, appear as a piece of “small seedlings.” This kind of nursery stock not only can not be planted, affecting the economic benefits, but also affects the afforestation rate. In response to this problem, we used in 1980, stubble, shoot two measures were tested. In the autumn investigation, the effect of stumping was better than that of stubble cutting. The average seedling height and diameter were respectively 65cm and 0.28cm more than those of stubble stubble, and the dry matter consumption and soil power consumption of last year due to stubble were reduced. To this end, in 1981 on the issue of the intensity of the tip were studied, the results are summarized below, for the production and research units for reference.