杨粮间作系统小气候研究

A study on microclimate under poplar-crop intercropping systems.

4年农田杨粮间作系统小气候测定结果表明,杨粮间作条件下农田小气候发生了明显的变化,与对照相比,毛白杨幼林使间作农田平均气温下降1.0～1.2℃,湿度提高4.1％～12.2％,风速降低32.1％～59.8％,而毛白杨成林对间作农田的影响也有相似结果,且林木的不断生长对农田的遮荫度也逐步加大。为保证间作作物产量,林木行距20m左右时其间作应不超过6年,30m行距时其间作应不超过10年。为保证间作的稳定性和长期性,建议实行大行距(30m以上)间作方式。

Four years investigation showed that the farm microclimate has a great change under poplar-crop inter-cropping system. In comparison with the non-tree control, the average air temperature and wind speed in inter-cropping farm are decreased by 1.0-1.2℃ and by 32.1%-59.8% respectively, but the relative air humidity is increased by 4.1%-12.2%. And the change of farm microclimate leaded by near-mature poplar stand has the sim-ilar consequence. The tree shading degree, on the other hand, becomes more and more serious following with poplar growing. In order to maintain crop output, the intercropping duration will not over 6 years when the poplar spacing is about 20m, but it will prolong for 10 years when it is 30m. It is suggested that the poplar spacing be-tween rows should be over 30m and its branches should be pruned regularly to ensure the stability and long-term of the intercropping system.