Effects of Biochar, Vermicompost and FYM on Soybean Productivity and Nutrient Use Efficiency in Vertisols

Abstract

Soybean productivity in Vertisols is often constrained by poor nutrient availability and low nutrient use efficiency due to soil-related limitations. Organic amendments such as biochar, vermicompost and farmyard manure (FYM) can improve soil fertility, enhance nutrient retention and support sustainable soybean production. This study evaluated the effects of biochar, vermicompost and FYM on soybean productivity and nutrient use efficiency in Vertisols. A field experiment was conducted during Kharif 2024 at SVVV, Indore, using a randomised block design with eight treatments. These included 100% recommended dose of fertiliser (RDF) and various INM modules comprising 50% RDF combined with biochar, FYM and vermicompost. The parameters studied included yield, NPK uptake and nutrient efficiency indices. Integrated treatments significantly outperformed sole chemical fertilisation. Treatment T8 (50% RDF + 2.5 t biochar + 2.5 t VC ha⁻¹) recorded the highest grain (12.52 q ha⁻¹) and straw (18.74 q ha⁻¹) yields, representing a 100% increase over the control. T8 also exhibited the maximum nitrogen and potassium uptake in grain and superior physiological efficiency for nitrogen. While soil pH and EC remained stable, organic carbon showed slight improvement under biochar-based treatments. Higher soil NPK in the control plots compared with T8 reflected efficient nutrient utilisation and higher biomass removal in the integrated plots. Substituting 50% RDF with a biochar-vermicompost blend (T8) optimises soybean productivity and nutrient recovery through a slow-release mechanism, offering a sustainable strategy for soil health and crop performance in black soils.