APEX 모델을 이용한 경사밭 고랑 식생 피복에 따른 인 유출 저감 평가

Abstract

Best Management Practices (BMPs) are proactive strategies to mitigate agricultural non-point source (NPS) pollution. Among non-structural BMPs, furrow vegetative cover reduces runoff velocity and prevents soil loss by introducing cover crops in furrows. However, field monitoring of NPS pollution reduction is often constrained by environmental factors, time limitations, and high costs. Therefore, this study aimed to evaluate the effectiveness of furrow vegetative cover in reducing phosphorus runoff in sloped upland areas using the APEX model. The study was conducted in a sloped upland field at the National Institute of Agricultural Sciences in Wanju-gun, Jeollabuk-do, South Korea. Model calibration was performed by comparing simulated values with observed monitoring data. The control treatment involved conventional fertilization management and crop cultivation, while the experimental treatment applied furrow vegetative cover in addition to the control conditions. Model validation demonstrated a strong agreement between simulated and observed runoff and phosphorus loads, with R² = 0.96, NSE = 0.95, and PBIAS = 12.5% for runoff, and R² = 0.72, NSE = 0.65, and PBIAS = 23.5% for total phosphorus (T-P). Under historical climate conditions (1991–2020), the analysis revealed that furrow vegetative cover reduced runoff by up to 20.3% and T-P by up to 50.4%. The results of this study indicate that furrow vegetative cover is significantly effective in mitigating agricultural NPS pollution. Future research should focus on scenario-based modeling to assess the long-term impacts of BMPs under climate change conditions and explore the applicability of other BMPs.