ABSTRACT

A field experiment was conducted to know the effect of distillery byproducts on soil zinc and iron fractions in rabi sorghum under calcareous Vertisol at experimental sites of RARS, Vijayapura during rabi 2023-24. The experiment was laid out in randomized complete block design with eleven treatments and three replications. The treatments were consisted; T1: FYM at 3 t ha-1; T2: Pressmud at 3 t ha-1; T3: Spentwash at 5 ml kg-1 of soil (1:10 dilution spentwash:water); T4: 3 t ha-1 [Spentwash + FYM (1:3 mixing and curing for 25 days)]; T5: 3 t ha-1 [Spentwash + Pressmud (1:3 mixing and curing for 25 days)]; T6: T1 + 100% RDF; T7: T2 + 100% RDF; T8: T3 + 100% RDF; T9: T4 + 100% RDF; T10: T5 + 100% RDF and T11: Absolute control. Results showed that the highest zinc fractions, iron fractions, enzymatic activities and soil microbial biomass were recorded in treatment received spentwash at 5 ml kg-1 of soil (1:10 dilution of spentwash and water) + 100% RDF and on par with spentwash at 5 ml kg-1 of soil applied alone followed by combined application of spentwash with FYM and spentwash with pressmud (both the combinations were mixed at 1:3 ratios and cured for 25 days) with 100% RDF. Highest uptake of nutrients, growth attributes, yield and B:C ratio of rabi sorghum were observed with spentwash at 5 ml kg-1 of soil (1:10 dilution of spentwash and water) applied alone or with recommended dose of fertilizers. The application of spentwash at 5 ml kg-1 of soil (1:10 dilution of spentwash and water) applied alone or with 100% RDF followed by the combined (mixing and curing at 1:3 ratio) application of spentwash with FYM are the best options for enhancing the soil fertility and crop productivity in dryland agricultural production.