Optimizing fertilizer use efficiency for Kimchi cabbage production in Highland Agriculture: Comparing slow and fast release fertilizers on varying slopes

Steep slopes in Gangwon's highland agriculture landscape accelerate soil erosion; reducing fertilizer efficiency and limiting Kimchi cabbage (KC) productivity.This study evaluated the performance of KC, KC nitrogen (N) content, uptake and use efficiency, and post-harvest soil fertility under slow-release (SRF) and fast-release (FF) fertilizer treatments across two slope gradients (15% slope lysimeter and flatland) in 2024.Both SRF and FF significantly improved plant growth and marketable yields compared to the 'no-fertilizer' control (NF), with no significant differences between the two fertilizers.Despite SRF supplying higher phosphorus (P) and potassium (K) doses, similar N levels in both treatments led to comparable N content, uptake and yield outcomes.Plant weight and head height were greater in the flatland, likely due to improved water retention and higher baseline soil fertility.Soil losses recorded in slope lysimeters under SRF and FF were lower than previous records, and did not significantly affect N availability or uptake.However, NUE was reduced in the slope lysimeter, likely due to other less favorable soil conditions.SRF proved promising in sloped environments, potentially due to its slow nutrient release mechanism, enhancing nutrient retention.The findings indicate the importance of terrain-specific fertilizer management, with SRF offering additional benefits in erosion-prone areas.Future studies should investigate long-term impacts of repeated fertilizer use under varying topographies, focusing on nutrient cycling, soil health, and environmental sustainability.