Abstract
The long-term sustainability of intensive vegetable production systems is threatened by soil degradation and environmental pollution from chemical inputs. A comprehensive seven-year field experiment (2018–2025) was conducted to identify effective organic strategies for tomato (var. PKM-1) cultivation on a medium black soil in Parbhani, India. The study evaluated ten nutrient management regimes in a Randomized Block Design with three replications. Treatments included variations of farmyard manure (FYM), vermicompost (VC), neem cake, Jivamrut applications, and an integrated organic package. Pooled results demonstrated that 100% recommended dose of nitrogen (RDN) through vermicompost (T₂) significantly (p < 0.05) outperformed other treatments, yielding the highest tomato fruit yield (22.60 t/ha), gross monetary returns (₹271,690/ha), net monetary returns (₹184,169/ha), and benefit-cost ratio (3.03). This treatment also produced superior fruit quality, evidenced by the highest lycopene content (9.77 mg/100 g), number of fruits per plant (23.86), and individual fruit weight (48.55 g). Treatment T₂ was statistically on par with T₃ (50% RDN through FYM + 50% RDN through VC) for most agronomic and economic parameters. Post-harvest soil analysis revealed that T₂ and T₉ significantly enhanced the soil’s chemical fertility (available N, P, K, and micronutrient status). Nutrient uptake studies confirmed the efficient translation of soil health improvements into plant nutrient assimilation. The study also meticulously tracked year-on-year variations in yield and soil properties, revealing consistent performance trends and the gradual improvement of soil fertility under specific organic amendments. This seven-year, single-site study on a medium black soil demonstrates that, under the tested semi-arid tropical conditions, the consistent application of vermicompost emerged as the most effective organic nutrient management strategy, delivering competitive productivity, economic viability, and enhanced soil fertility. The results suggest that vermicompost can be a cornerstone practice for organic tomato systems in similar agro-ecologies, though validation across a wider range of environments is recommended. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1038/s41598-026-41738-2.