不同覆盖度下盆栽小白菜蒸散与水分利用效率

通过盆栽试验，研究了不同覆盖度条件下小白菜所处小环境的温湿度动态，以及作物蒸腾和盆栽基质蒸发的耗水规律。结果表明：植株生长点的温湿度随覆盖度的增大而增加。昼夜蒸散量随覆盖度的增大而减小，白天蒸散量变化显著，无覆盖处理白天蒸散量为最大，1/2圆覆盖处理仅次于无覆盖处理，15/16圆覆盖处理最小。小白菜从出苗到收获总的耗水量随覆盖度增大而减小，1/2圆覆盖、3/4圆覆盖、15/16圆覆盖处理的总耗水量分别为无覆盖处理的91.34%、69.03%和40.74%。无覆盖、1/2圆覆盖、3/4圆覆盖、15/16圆覆盖处理的地上部干物质质量的平均值分别为5.551、6.536、5.143、3.345 g，其水分利用效率的平均值分别为1.53、1.97、2.05、2.25 kg/m3。试验总结表明盆栽小白菜的水分利用效率随着覆盖度的增加而增加，15/16圆覆盖处理最高。

Evapotranspiration and water use efficiency of potted pakchoi under different surface coverage degrees

Through pot experiment, dynamic changes of temperature and humity in micro-environment at growth period of pakechoi, and water consumption rules of crop transpiration and planting substrate evaporation were studied under different coverage degrees. The results showed that the air temperature and humidity increased with the coverage degrees increasing at growth point. During day and night, evapotranspiration decreased with increasing of coverage degrees. The variation of daytime evapotranspiration was significant, the order of evapotranspiration was the no-coverage treatment >1/2 coverage treatment >15/16 circle coverage. The total water consumptions tended to decrease with coverage degrees increasing during pakchoi growth period. Water consumption of 1/2 circle coverage, 3/4 circle coverage, and 15/16 circle coverage were 91.34%, 69.03% and 40.74% of the none coverage treatment, respectively. To none coverage, 1/2 circle coverage, 3/4 circle, and 15/16 circle, and their corresponding average dry weights of the aerial parts were 5.551, 6.536, 5.143, 3.345 g, and their corresponding water use efficiency were 1.53, 1.97, 2.05, 2.25 kg/m3. The above results indicated that the water use efficiency of pakchoi increased with the increasing of coverage degrees, the maximum value of water use effiieny appeared at 15/16 circle coverage treatment.