Integrated Organic and Organo–Mineral Fertilization Effects on Yield Performance and Quality Attributes of Tomato (Solanum lycopersicum L.)

Abstract

This study aimed to determine optimal rates of organic and organo–mineral fertilizers for achieving high yield and quality of tomato under irrigated gray–brown (chestnut) soils of the Kazakh–Tovuz economic region. Field experiments showed that manure application at 30 t/ha produced 52.0 t/ha, increasing yield by 22.6 t/ha (77.0%) compared to the unfertilized control, while the highest yield (53.6 t/ha) was obtained with combined application of manure 15 t/ha + N75P37.5K90, exceeding the control by 82.3%. Fertilization also improved fruit quality, increasing dry matter (by 0.3–1.5%), total sugars (0.3–1.1%), and vitamin C (1.1–5.0 mg/kg), while reducing titratable acidity; nitrate content remained within safe limits. The best quality indicators were recorded under the combined treatment, with dry matter reaching up to 8.2%, total sugars up to 4.4%, and vitamin C up to 24.6 mg/kg. Overall, the combined use of organic and mineral fertilizers proved most effective, ensuring high productivity, improved fruit quality, efficient nutrient use, and maintenance of soil fertility under the studied conditions. Keywords: Tomato, gray–brown (chestnut) soil, organic and organo–mineral fertilizers, soil fertility, yield, quality