旱区间作水分高效利用机制探讨

间作系统充分利用光热水肥资源具有高产高效特征，在旱区得到了广泛应用。综合国内外间作群体水分利用的研究成果，论述了间作具有水分优势的高效利用机制。间作系统减少土壤蒸发、提高作物蒸腾、降低棵间蒸发与耗水量的比值，增加土壤水分的有效性，提高作物根系对土壤水分的吸收利用，进而提高水分利用效率。间作系统的水分利用机制包括生态位分离减少竞争以促进资源的充分利用、水力再分配调节作物及邻体作物土壤的水分条件缓解旱区作物的水分胁迫。间作系统水分利用的影响因素包括作物种类、种植密度和空间布局、水肥管理和耕作措施。针对研究中的不足，指出未来间作系统水分高效利用研究应关注以下方面：不同区域间作群体增产和节水的规律；水分与源库关系及对种间关系的响应；量化水分与根系生长的关系，建立间作作物对水分吸收的模型；地下部对间作水分优势的响应。

Mechanism of high\|efficient water use of intercropping in arid regions

Crop intercropping system has been widely used in arid areas due to high grain yield and efficient use of resources such as light, radiation, water, and nutrient. The mechanism of water use advantage in intercropping system was discussed based on the previous research about water use of intercropping. The results showed that intercropping reduce soil evaporation and the ratio of evaporation and evapotranspiration, increased the availability of soil water, improved crop transpiration and the absorption and utilization of soil water by crop roots and then improve water use efficiency. The water use mechanism of intercropping system including niche differentiation reduced competition and promoted the full use of resources and water redistribution regulated the soil water content of crop and adjacent crop to alleviates the water stress of crops in arid areas. The major regulation factors for efficient water use in intercropping included crop species, sowing density and spatial arrangement, water and fertilization management, and tillage measures. Further studies about water efficient use in intercropping system include the mechanism of yield increase and water saving of intercropping in different regions; the relationship between water and source\|sink and response to interspecific relationship; quantization the relationship between water and root growth to establish a model on water absorption by intercropping crops and response of underground to water use advantage in intercrops.