The expansion of protected horticulture in Korea and the increasing adoption of hydroponic cultivation have intensified the need to manage hydroponic nutrient solution effluent (waste nutrient discharge). This study aimed to assess the spatial distrib...
The expansion of protected horticulture in Korea and the increasing adoption of hydroponic cultivation have intensified the need to manage hydroponic nutrient solution effluent (waste nutrient discharge). This study aimed to assess the spatial distribution of facility greenhouses in the Geum River basin and to estimate basin-scale effluent discharge loads to support management planning. Facility-horticulture spatial coverage data (SHP) from the Palm Map platform were obtained from the electronic agricultural land map and overlaid with the Geum River basin boundary using GIS. Facility-greenhouse areas were calculated and aggregated by tributary sub-basins. The total facility-greenhouse area within the Geum River basin was estimated at approximately 14,565 ha, representing 26.6% of the national facility-greenhouse area (54,844 ha). Facility greenhouses were most densely distributed around the Gongju reach of the Geum River, the Nonsan Stream sub-basin, and the Geum River estuary, which together comprised 35.9% of the total facility-greenhouse area within the basin. Farm surveys showed that tomatoes (including cherry tomatoes) were the dominant crop in Sedo-myeon (226 of 290 farms), whereas cucumbers were most common in Mokcheon-eup (103 of 174 farms). Soil-based cultivation remained prevalent (92% in Sedo-myeon and 89% in Mokcheon-eup), while hydroponic cultivation accounted for approximately 10%.
Effluent discharge loads were estimated by multiplying crop-specific unit discharge factors reported in previous studies by tributary-scale facility-greenhouse areas. These results provide a basin-wide baseline for prioritizing management areas and sizing required treatment capacity to support pollutant-reduction strategies for sustainable protected horticulture in the Geum River basin.