Balancing Resource Circularity and Farm Profitability: A Secondary Probabilistic Bioeconomic Assessment of Partial Nutrient Solution Recirculation in a Korean Indoor Strawberry System

Partial nutrient-solution recirculation can improve resource efficiency without establishing net environmental sustainability or private profitability. This secondary bioeconomic assessment used four fixed-layout operational records per setting for 0%, 30%, and 50% recirculation in a Korean two-tier indoor aeroponic strawberry system. Resource indicators were integrated with partial budgeting, 200,000-draw Monte Carlo simulations, downside-risk measures, complementary uncertainty cases, Sobol sensitivity analysis, and capital-recovery and avoided-discharge shadow-value frontiers. Thirty-percent recirculation reduced freshwater make-up by 30.0% and freshwater intensity by 28.3%, while retaining 97.7% of control yield. At the base price and tariff, its incremental margin was −8364 Korean won (KRW), approximately −6.09 United States dollars (USD), per (25/3) m2 block-cycle; parity required 98.54% yield retention. With the observed mean yield difference fixed, the scenario-conditional positive-margin probability was only 2.95%. It was 24.94% under four-record empirical resampling and 55.35% under an exploratory triangular yield envelope, falling to 16.56% when declared labor and energy/consumables burdens were added to that envelope. The triangular result interpolates across sparse, non-independent records and is not a more empirically supported probability estimate. All probabilities assume independent model inputs and retained, incompletely auditable fertilizer-cost allocations. Fifty-percent recirculation remained unfavorable because yield losses outweighed input savings. These findings identify a resource–profitability trade-off, not an environmentally sustainable or optimal recirculation rate; numerical conclusions require independent crop-, facility-, and market-specific evidence.