灌溉方式与气象因子对华北平原小麦玉米生长与耗水的影响OA

Water scarcity and grain production present a prominent contradiction in the north China Plain,making water-saving irrigation of significant importance.Previous studies reveal that 40%of farmland water consumption is linked to ineffective soil evaporation.Although the underlying mechanisms and effects of subsurface drip irrigation(SDI)are still unknown,it can effectively reduce the water loss caused by soil evaporation. Through a long-term SDI field experiment at the Luancheng experimental station located in Shijiazhuang City,Hebei Province,this study compared soil moisture distribution,evapotranspiration(ET)dynamics,biomass accumulation,yield,and water use efficiency between SDI and conventional surface irrigation(SI).The effects of environmental factors on the seasonal dynamics of biomass and ET were investigated using correlation analysis. The results show that SDI significantly reduces ET compared to FI,with an average annual decrease of 10.8%during the wheat season and 3.0%during the maize season.The water use efficiency increased accordingly,rising by 12.4%in the wheat season,while remaining significantly higher in the maize season.SDI improved wheat yield stability by lowering the interannual coefficient of variation from 24.7%to 18.3%.However,maize yield variability increased by 2.5%,predominantly due to differences in rainfall.Analysis of environmental influence mechanisms revealed that under SI,soil moisture in the 0-10 cm surface layer predominantly regulates ET and biomass,with surface drought being the main limiting factor.Changes in soil moisture from the 10-20 cm layer to deeper depths had a greater effect on ET and biomass under SDI,suggesting that SDI successfully lowers evaporation and lessens surface-layer stress on crop growth.Solar radiation and air temperature showed significant positive correlations with ET and crop growth(P<0.05),representing key meteorological drivers affecting farmland water consumption,crop growth,and yield formation. SDI exhibits efficient water-saving and yield-enhancing benefits by optimizing the vertical distribution of soil moisture.To support the sustainable use of agricultural water resources in the north China Plain,future efforts should concentrate on improving fertilization and irrigation schedules and creating climate-adaptive irrigation strategies.