滴灌条件下地膜覆盖对玉米田间土壤水热效应的影响

水热条件是影响作物生长和发育的重要因素之一,通过田间试验研究了有膜滴灌和无膜滴灌对玉米的土壤水分和温度的变化。结果表明:在玉米生长前期,有膜滴灌0~20cm土层的含水率较无膜滴灌高出6.4%,差异显著(p0.05),但在30~100cm土层,有膜滴灌土壤含水率却比无膜滴灌低6.1%~7.54%,差异显著(p0.05)。玉米生育期前期(5-6月),覆盖地膜比无膜措施平均温度高0.4~4.1℃;种植后30d,覆盖地膜处理在5~10cm土层的日较差显著高于无膜处理,但其他土层差异却不显著,可见地膜覆盖在玉米生育期前期可以增加土壤浅层温度,提高土壤表层含水率,为玉米的生长发育提供了良好的水热条件。

Effects of Plastic Mulching of Maize on Soil Water and Temperature under Drip Irrigation

Hydrothermal Condition is one of the important factors affecting the growth and development of crops .The change of tem-perature and moisture is studied under the condition of cultivation with plastic film mulching and no film covering .The results show that the maize can take better advantage of soil water in the deep layers in the treatment of plastic film mulching than in the treat-ments of no film covering at seeding stage under less rainfall condition ;in the early grow th stage of maize at the topsoil (0~20 cm) , the soil water content in the treatment of plastic film mulching is 6 .4% higher (p<0 .05) than that of no film covering ;however ,at the layer of 30 to 100 cm depth ,the water content in plastic film mulching treatment is 6 .1% to 7 .54% lower (p<0 .05) than that in the treatments of no film covering ;the treatment of plastic film mulching has significant (p<0 .05) effects on the soil temperature mostly at the seeding stage and the decline stage when the crop area covering the soil is smaller than that in any other stages .How-ever ,the effects of soil temperature on the growth of crops are more important in the earlier stages than that in middle and late sta-ges .The soil temperature of plastic film mulching treatment in the early growth stage of maize (May ,June) is 0 .4 to 4 .1 ℃ higher than that of no film covering treatment .After 30 d of cultivation ,the diurnal range of film mulching treatment is significantly higher than that in non treatment in the 5~10 cm soil layer ,but has little difference for other depth layers .Therefore ,it can be concluded that the treatment of plastic film mulching increases the soil surface temperature and water use efficiency of maize in the early grow th stage ,and provides a better water and temperature condition for maize growth .