Effect of inorganic fertilizers in combination with biogas slurry and compost on production and quality of white onion (Allium cepa L.)

An experiment was carried out at Jain Hi-Tech Agri Institute, Jain Hills, Jalgaon, Maharashtra, India, to ascertain the suitable doses of Inorganic fertilizers in combination with Biogas slurry and compost during Kharif season 2014. Treatments were essentially recommended dose of fertilizer (RDF) (T-1), 75% RDF + 2 t ha(-1) compost (T-2), 50% RDF + 4 t ha(-1) compost (T-3), 25% RDF + 6 t ha(-1) compost (T-4), 8 t ha(-1) compost (T-5), 75% RDF + 2 t ha-1 Biogas slurry (T-6), 50% RDF + 4 t ha-1 Biogas slurry (T-7), 25% RDF + 6 t ha(-1) Biogas slurry (T-8), 8 t ha(-1) Biogas slurry (T-9) and 10 t ha(-1) Biogas slurry (T-10). Half of these were applied as basal dose (at transplanting), 25% were applied 30 days after transplanting (DAT) and remaining 25%, 45 DAT. This experiment was carried out using Randomized Block Design (RBD) with three replications. White onion cultivar 'JISL-5' used in this study possesses high solids and is being used for dehydration. The results revealed that there were significant differences (p < 0.05) in average bulb yield, bulb weight, average total soluble solids (TSS). Highest yield (16.98 t ha(-1)) was obtained from the plot treated with inorganic fertilizers (T-1) followed by T-6 (13.957 t ha(-1)), T-10 (13.491 t ha-1) and T-7 (13.329 t ha(-1)). Lowest yield was obtained in the treatment T-4 (5.409 t ha(-1)). The inorganic fertilizers appear to have compensated with slow release of nutrients from the biogas slurry and their combined effects may have increased the yield. There were no significant differences in growth parameters such as plant height and number of leaves.