林木遮荫对西宁地区油菜田的光照效应

Photoeffect on Rape Fields under the Condition of Woods-sunshade in Xining

对林木遮荫油菜花角期田间光照变化观测。结果显示,遮荫使田间光照平均被削弱45%—47%,光强降低2.73万Lx-2.8万Lx,大于光饱和点日照时数减少2.5h-3.4h。光照不足是影响产量的主要因素。

The illumination situation of woods-sunshade field was observed at blooming and podding stages of rapeseed crop（ Brassica campestris）. The result showed that the strength of illumination in the woods-sunshade field was weakened by the ratio of 45% ～ 47%, namely photometric reading went down by 2.73 × 10^4Lx ～ 2.8 × 10^4Lx, 2.5～3.4h of sunshine time more than photo saturation point was reduced, obviously rapeseed yield will decrease when the sunshine is inadequate.