Study on Soil Evaporation of Flue-Cured Tobacco and its Main Driving Factors under Water and Nitrogen Coupling Condition

A pot experiment was conducted on soil evaporation of flue-cured tobaccounder water and nitrogen fertilizers coupling treatmentsin this study. Soil evaporation at each growth stage of tobacco were analyzed, so did ratio of average soil evaporation (AEa) to mean water consumption (AET). Some factors impacting soil evaporation were also investigated. The results showed that average daily soil evaporation was positively correlated with soil temperature (p<0.01), the equation between daily soil evaporation and surface soil moisture (θ) was AEa=0.058e0.048θ (R2=0.717), while relationship between the ratio of evaporation to water consumption (AEa/AET) and leaf area index (LAI ) was functioned as AEa/AET=0.201 LAI-0.912(R2=0.658). It also suggested that the best effects to decrease soil evaporation of flue-cured tobacco appeared in treatment of 6g N per plant combined with the irrigation amount and frequency at 4.5kg and 9 times, 18kg and 18 times, 13kg and 26 times at root spreading stage, vigorous growing stage and the maturing stage respectively.