夏玉米垄作覆盖对农田土壤水分及其利用影响

Influence of Bed-Planting and Strew Mulching System on Soil Water and Crop Using of Farmland

在小麦-玉米1年两熟雨养旱农区，将垄作和秸秆覆盖技术结合起来，进一步提高天然降雨的利用效率。试验结果表明，在0～40cm土层含水量，夏玉米垄作覆盖较平作有显著的提高，以5～10cm表现尤为突出，随着土层的加深，这种差异逐渐减少；玉米冠层蒸发量平作平均值分别高于平作覆盖、垄作和垄作覆盖12．8％，7．6％和13．2％，地面蒸发量平作平均值分别高于平作覆盖、垄作和垄作覆盖48．6％，29．9％和54．3％；垄作覆盖比平作水分利用效率提高24．32％，叶片失水率较低。这说明了垄作覆盖能最大程度将天然降雨蓄存在土中，并转化为作物可用水资源。

In order to explore the resource of rain-fall under rain-fed regions of wheat-summer corn planting system, it is useful measures to combine bed-planting and strew mulching for improving water use efficiency （WUE）. The experiment showed the summer corn cultivation of combinating bed-planting with strew mulching markedly increased the amount of soil water storage from 0～40 cm deep soil profile, especially in the scope of 5～ 10 cm, in contrast with the flatting cropping system. But the effects gradually decreased as soil profile extended deeply. The average value of free vaporizing on the top of corn population was 12.8%, 7.6%, 13.2% for the treatments of sole cropping with mulching, bed-planting, combinating bed-planting with mulching, respectively, in comparison with the treatment of sole cropping, but the average value of ground vaporizing 48.6% ,29.9%, 54. 3%, respectively. The system of bed-planting and mulching improved WUE by 24.32%, and the rate of leaf losing water was the lowest among the four treatments. The results implicate that the pattern of bed-planting and mulching can effectively storage rain fall, and translate the soil water resource into plant water available at most.