Slope construction increased surface drainage but caused drought stress on soybean growth at Saemangeum reclaimed tideland

Reclaimed tidelands (RTLs) in Korea were originally developed for rice cultivation; however, converting paddy to upland field is encouraged to improve grain self-sufficiency.However, due to poor drainage, high salinity, and low nutrient availability, cultivating upland crops in RTLs have many challenges.Furthermore, frequent extreme weather events, such as precipitation, heatwaves, and droughts, uncertainty of cultivation management is increasing.Therefore, this study was conducted to evaluate the effect of slope construction on improving drainage through soil water content, and to analyze the effects of drought on soil water and soybean (Glycine max L. Merr.) growth in sloped and flat fields.Slope construction, in combination with high saturated hydraulic conductivity (0.07 cm hr -1 ) and surface drainage, led to a rapid decrease in soil water content after rainfall, which is benefit to reduce excess moisture injury for soybean during heavy rain season.However, after monsoon season, low precipitation caused soil water content to drop below 10%.Furthermore, prolonged high temperature from July to September, which includes flowering and pod-filling stages, caused sterility of pods and reduced overall yield.Such yield reduction was more prominent in sloped plot due to improved drainage efficiency.This study highlights the need for effective climate-resilient water management strategies, including irrigation and drainage, to support sustainable soybean cultivation in reclaimed tidelands.