西北干旱区滴灌棉田膜间土壤蒸发试验研究

膜间土壤蒸发是覆膜棉田水分消耗的主要组成部分，在干旱少雨的新疆石河子利用微型蒸渗仪观测了地下滴灌和膜下滴灌条件下，覆膜棉田膜间土壤水分蒸发，并对膜间不同位置处的土壤蒸发规律进行了试验研究，研究结果表明，滴灌条件下膜间土壤水分蒸发分别与气温、辐射、饱和水汽差以及相对湿度呈指数相关关系，与参考作物需水量呈线型相关关系，与表层土壤含水率呈指数关系；膜间土壤累积蒸发量在苗期最高、其次是花铃期、吐絮期最小；膜下滴灌条件下膜边土壤的蒸发量高于膜间（两条膜正中间的裸地）蒸发量；地下滴灌条件下，错位种植会导致灌溉水的无效蒸发，不利于灌溉水的高效利用。

Experimental Research on Soil Evaporation of Cotton with Drip Irrigation under Mulch in Arid Areas in Northwest China

Soil evaporation is an important component of water consumption in cotton with drip irrigation under mulch. Field experiments were conducted to investigate the soil evaporation between the mulch on cotton with drip irrigation (surface and subsurface drip irrigation) under the mulch with micro-lysimeter, the change law of soil evaporation on different points was studied. The results showed that there was a good exponential function relationship between soil evaporation and air temperature, saturation vaporpressure difference, solar radiation, relative humidity, soil water content, respectively, and there was a linear correlation between soil evaporation and reference crop evapotranspiration; cumulative soil evaporation of between the mulch is the highest at the seedling stage, the second at the blossoming and boll forming stages, the lowest at the boll opening stage; soil evaporation is higher at lateral of mulch than at the middle of the point between the mulch. That will lead to inefficient evaporation of soil water and the decrease in the irrigation water use efficiency with subsurface drip irrigation under plastic mulch when planting is dislocated.