Mulch-Mediated Enhancement of Physiological Performance and Macronutrient Status in Mandarin (Citrus reticulata Blanco) Cultivation Under Semi-Arid Vertisol Conditions

Abstract Purpose This study investigated how organic versus synthetic mulching systems influence soil-plant water relations and nutrient dynamics in Nagpur mandarin through mechanistic evaluation of physiological responses and soil microbial activity in semi-arid conditions where water stress and nutrient deficiencies limit citrus productivity. Methods A randomized complete block design compared nine treatments over eight months: control, synthetic mulches (silver, black, transparent polythene, Weedmat), and organic mulches (mustard straw, coriander straw, jamun leaves, soybean straw). Parameters measured included soil water-holding capacity, plant water status, gas exchange, stress indicators, leaf macronutrients (N, P, K), and soil microbial populations. Results Organic mulches enhanced soil water-holding capacity (15.2% increase with jamun leaves) and maintained superior plant water status (relative water content: 85.28% vs 75.00% control). Jamun leaves mulch optimized gas exchange (stomatal conductance: 17.66 mmol m⁻²s⁻¹; photosynthetic rate: 8.85 µmol CO₂ m⁻²s⁻¹) while reducing stress indicators (proline: 0.25 vs 0.36 µmol g⁻¹ control). Leaf nutrient concentrations increased significantly under organic treatments (N: 2.27%, P: 0.29%, K: 1.32%). Soil fungal populations increased 30–40% under organic mulches, indicating enhanced biological activity driving nutrient mineralization. Conclusion Organic mulches, particularly jamun leaves, create synergistic soil-plant interactions through improved water retention, enhanced microbial-mediated nutrient cycling, and optimized rhizosphere conditions, functioning as integrated soil conditioners that simultaneously address water stress and nutrient limitations in citrus production systems.