Synergistic effects of organic amendments and reduced mineral fertilization on potato productivity, nutritional quality, economic profitability, and environmental performance under E gyptian field conditions

Abstract This study evaluated whether partial substitution of mineral NPK fertilizers with organic amendments can sustain or improve potato productivity while enhancing tuber quality, profitability, and environmental performance under Egyptian field conditions. The main research question was whether integrated nutrient management provides a more sustainable alternative to sole mineral fertilization for different potato cultivars. Two‐season field experiments were conducted in Middle Egypt using a randomized complete block design. Eight fertilization regimes combining mineral NPK with chicken manure, compost, and vermicompost were tested on two commercial potato cultivars, “Lady Balfour” and “Cara.” Agronomic growth, tuber yield, physiological traits, tuber nutritional quality, economic return, and fertilizer‐related environmental indicators were assessed. Integrated fertilization improved vegetative growth compared with sole mineral fertilization. Plant height increased by up to 30%, branch number by nearly 78%, and stem number by approximately 55%. Tuber diameter increased by up to 35%, and total tuber yield reached about 14.8 t feddan −1 (feddan = 4200 m 2 = 0.42 ha) under the best integrated treatment, representing a 6–7% increase over the mineral fertilizer control. Chlorophyll and carotenoid contents increased by 23–32%, while tuber N, P, K, and total soluble solids improved. Partial mineral fertilizer replacement also reduced estimated greenhouse gas emissions while maintaining or improving economic return. Partial substitution of mineral NPK with organic amendments is a practical strategy for sustainable potato production in Egypt, improving yield, physiological performance, tuber quality, profitability, and environmental sustainability.