Sustaining soil health and tomato production through organic inputs and bacterial inoculations in alluvial soils detoxifying plant contaminants

Abstract

The demand for organic tomatoes is gaining momentum globally, especially for their nutritional quality, shelf-life, and yield sustainability. Similarly, the restoration of metal-contaminated soils and maintenance of soil health is getting momentum through the application of organic inputs and microbial inoculations in soils. The present study evaluates different concentrated organic inputs and biofertilizers with a minimal dosage (14.3% of the recommended dose of fertilizers or RDF) under a field experiment conducted at the Agricultural Farm of Amity Institute of Organic Agriculture, Amity University, Noida, Uttar Pradesh, India. Organic treatments included mustard cake, goat manure, poultry manure, farmyard manure (FYM), neem cake, and biofertilizers (Azotobacter and phosphate solubilizing bacteria, or PSB). FYM (15 t ha−1) and vermicompost (VC 3.0 t ha−1) (T5), and the optimized inputs (containing the dual inoculation of Azotobacter and PSB, a mixture of organic inputs, and 14.3% RDF (T11) significantly improved plant height, number of branches/leaves/fruits, carotenoids, lycopene, fruit weight, yield, ascorbate peroxidase, total antioxidants, superoxide dismutase, total soluble solids (TSS), Vitamin C, and shelf-life in tomatoes. Organic inputs and inoculation of Azotobacter and PSB significantly reduced the concentration of Cd, Cr, and Pb from soils. The authors conclude that (a) the combined application of FYM and VC, and (b) the optimized mixture of bulky and concentrated organic inputs, 14.3% RDF, and the dual inoculation can improve the nutritional quality, minimize heavy metals (Cd, Cr, and Pb), and overall, sustain tomato production in the hot semi-arid alluvial sandy loam soils. The optimized organic inputs with dual microbial inoculations harness the climatic conditions in tropical regions to facilitate better color and ripening, and other quality parameters leading to higher lycopene contents in tomatoes.