科尔沁沙地南缘玉米液流特征OA

Water availability is a key environmental factor constraining plant growth,development,and surviv-al.Plant stem flow rate can reflect the physiological activity status of crops.This study focused on maize in the southern fringe of the Horqin Sandy Land,using the heat balance sap flow monitoring technique to observe stem flow and environmental factors during the vigorous growth period of maize from July to September 2024.The characteristics of maize stem flow and its response mechanism to environmental factors in the sandy land were analyzed.The results showed that the average daily stem flow rate of maize was 220.57 g/d,with higher rates from the tasseling to the filling stage and a significant decrease during the maturity stage.On an hourly scale,stem flow rate was positively correlated with vapor pressure deficit(VPD),solar radiation,and wind speed,but negatively correlated with precipitation.Stepwise regression analysis revealed that the main environmental fac-tors influencing maize stem flow rate were VPD and solar radiation,which together explained 69.7%of the var-iation in stem flow rate.Contribution rate analysis further indicated that VPD had a higher contribution rate(58.09%)to stem flow rate than solar radiation(41.91%),particularly in September,when it became the sole dominant factor(contribution rate 100%).This study reveals that in the arid sandy environment of the southern fringe of the Horqin Sandy Land,vapor pressure deficit is the most critical environmental factor driv-ing maize transpiration.The findings provide a theoretical basis for scientifically managing water use in sandy land maize,improving yield,and promoting sustainable agricultural development in the region.