Sustainable Nutrient Management in Mentha: Integrating Soil Health, Crop Productivity, and Essential Oil Quality for Climate-Resilient Cultivation

Abstract

Commercial Mentha production is frequently managed as a high-input system because rapid canopy development, repeated harvests and substantial nutrient removal underpin profitable herb and essential-oil yields. This production logic can create a three-way management problem: nutrient supply must sustain biomass, preserve the chemical quality of the oil and avoid progressive deterioration of soil physical, chemical and biological functions. This critical narrative review evaluates evidence on mineral fertilisers, organic amendments, distillation-residue recycling, microbial biofertilisers and integrated nutrient management in Japanese mint, peppermint and related cultivated mints. Literature published from January 1990 to 9 April 2026 was identified through accessible scholarly indexes, bibliographic databases, DOI records, institutional repositories and citation searching. Evidence was appraised according to experimental design, duration, soil characterisation, treatment comparability, oil analysis, replication and field relevance. Nitrogen is the nutrient with the clearest and most reproducible influence on canopy growth and oil yield, but its effects on oil concentration and monoterpene composition are non-linear and strongly conditioned by genotype, water supply and harvest stage. Phosphorus, potassium and micronutrient responses are less securely resolved because they are often tested within compound fertiliser treatments or short pot experiments. Organic amendments can improve soil carbon, aggregation, nutrient buffering and microbial activity, yet their nutrient-release patterns may not coincide with peak crop demand. Plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi have plausible mechanisms for improving nutrient acquisition, stress tolerance and glandular-trichome activity, although much of the evidence remains strain-specific and greenhouse-based. The strongest agronomic case is therefore for adaptive integration rather than categorical replacement of mineral fertilisers: soil- and plant-informed nutrient budgets, synchronised mineral inputs, quality-controlled organic resources, locally validated inoculants, coordinated irrigation and routine chromatographic assessment of oil composition. Long-term, multi-location trials that measure nutrient-use efficiency, soil function, emissions, leaching, oil quality and profitability are required before universal recommendations can be justified.