干旱区滴灌枣棉间作模式下枣树棵间蒸发的变化规律

为明确枣树单、间作棵间土壤蒸发及水分耗散特征。通过大田试验,采用MLS测定枣树单、间作棵间土壤蒸发,并对其土壤蒸发的变化规律和气象因素、土壤因素及边界效应进行试验研究。试验结果表明:枣树棵间土壤蒸发在各生育期均出现不同的差异性。单、间作棵间土壤蒸发量及植株蒸腾量存在显著差异且总体上单作高于间作。对外部影响因素进行研究,枣树棵间土壤蒸发与太阳辐射、土壤含水量等呈现良好的函数关系。但日均温仅与单作棵间土壤蒸发相关性较高,而与间作相关性较差。对间作枣树边界效应进行判别,间作棉花显著影响间作枣树行间棵间土壤蒸发量,且棉花叶面积指数与行间棵间土壤蒸发量呈现良好二次函数关系。该研究在一定程度上体现了间作模式的优势,为其对减少无效水分消耗,提高水分利用效率提供理论依据。

Study on evaporation variation of jujube trees under drip irrigation of jujube and cotton intercropping in an arid area

This study was conducted in order to clarify the characteristics of soil evaporation and water dissipation in jujube trees and intercropping trees. On the basis of field experiments, we examined the changes in soil evaporation, meteorological factors, soil factors, and boundary effect by means of micro-lysimeter monitoring of the soil evaporation of jujube trees and intercropping. The following results were obtained. Soil evaporation differed at the different growth stages of jujube trees. There were significant differences in soil evaporation and transpiration between single and intercropping trees, and it was generally higher in monoculture than with intercropping. Investigation of external influencing factors indicated that the soil evaporation of jujube trees showed a good functional relationship with solar radiation and soil water content. Although the daily average temperature was related to the soil evaporation of single cropping trees, the correlation with intercropping was poor. When the boundary effect of intercropping jujube tree was analyzed, it was found that intercropping cotton significantly affected soil evaporation between intercropped jujube trees, and the leaf area index of cotton showed a good 2-fold relationship with soil evaporation. To some extent, this study reveals the advantages of the intercropping model, which provides a theoretical basis for reducing inefficient water consumption and improving water-use efficiency.