Integrated Fertilization Improves Tomato Productivity, Fruit Quality, and Soil Properties

Intensive horticultural production relies heavily on mineral fertilizers, which may negatively affect soil quality and long-term sustainability. Integrated fertilization represents an alternative for reducing these risks; however, its effects on the soil–plant–fruit system remain incompletely understood. The objective of this study was to evaluate the effects of different integrated fertilization strategies, based on the combination of organic amendments and reduced chemical fertilization, on soil properties, tomato productivity, and fruit nutritional quality. Ten treatments with five replicates were evaluated under a completely randomized design in plants grown under a high-tunnel system. The results showed that integrated fertilization enabled a 40–50% reduction in macronutrient inputs and the complete elimination of micronutrient fertilization, while achieving yields that did not differ significantly from those of the chemical control and were 480–520% higher than those of the unfertilized control. In addition, integrated fertilization increased fruit concentrations of calcium, magnesium, phenolic compounds, and lycopene. Treatments incorporating organic amendments produced with the incorporation of Trichoderma sp. showed higher potassium concentrations in the fruit. Soil organic matter increased by 80–250%. These results indicate that integrated fertilization can reduce the use of mineral fertilizers while maintaining crop productivity and improving both soil quality and the nutritional and functional quality of the fruit.