Irrigation Method and Organic Water-Soluble Fertilizer Management Regulate Root-Zone Water and Nitrate-N Distribution, Yield, and Fruit Quality of Greenhouse Tomato

Irrigation and fertilizer management influences root-zone water and nitrogen distribution, yield, and fruit quality in greenhouse tomato production. Two soil-based greenhouse tomato experiments were conducted in 2025 and 2026 to evaluate the effects of surface drip and subsurface seepage irrigation combined with two organic water-soluble fertilizer formulations and three application rates on soil water content, nitrate nitrogen distribution, tomato growth, yield, and fruit quality. Soil water content and nitrate nitrogen were measured across five growth stages and four soil depths, and twelve fertilized management strategies were assessed using Pareto screening, stochastic multicriteria acceptability analysis, cross-cycle dominance, and rank stability. Subsurface seepage irrigation maintained higher root-zone water content and modified nitrate nitrogen distribution within the upper soil profile. The second fertilizer formulation improved yield and quality traits and reduced fruit nitrate nitrogen compared with the first formulation. Yield and quality traits increased from low to intermediate fertilizer application rates, whereas excessive fertilization increased fruit nitrate nitrogen accumulation. The integrated management strategy combining subsurface seepage irrigation with the second fertilizer formulation and intermediate application rate showed the most stable performance across growing seasons based on the multicriteria evaluation. These findings highlight the importance of coordinated irrigation and fertilizer management for regulating root-zone resources and improving greenhouse tomato production.