Impact of Organic Sources of Nutrients and Plant Growth Promoting Microorganisms on Yield, Soil Fertility and Economics of Elephant Foot Yam [Amorphophallus paeoniifolius (Dennst.) Nicolson]

Abstract

A field experiment was conducted during the 2024–2025 kharif season at the Experimental Farm of the Department of Vegetable Science, College of Horticulture and Forestry, Neri, Hamirpur, Himachal Pradesh, to assess the effects of organic nutrient sources and plant growth-promoting microorganisms on soil fertility, corm yield and the economics of elephant foot yam [Amorphophallus paeoniifolius (Dennst.) Nicolson] cv. Palam Zimikand-1. The experiment was arranged in a randomised complete block design with three replications and ten pre-planting corm treatments comprising cow urine, buffalo urine, slurries prepared from animal dung and urine, cow-dung slurry, beejamrit, Trichoderma viride, Pseudomonas fluorescens, Bacillus subtilis and water. Post-harvest soil samples were analysed for pH, electrical conductivity, organic carbon and available nitrogen, phosphorus and potassium. Treatment T9 (Bacillus subtilis) recorded the lowest soil pH (6.98) and electrical conductivity (0.189 dS m⁻¹), together with the highest organic carbon content (0.82%), available nitrogen (252.79 kg ha⁻¹), available phosphorus (25.95 kg ha⁻¹) and available potassium (161.37 kg ha⁻¹). The same treatment produced the highest corm yield (551.11 q ha⁻¹), gross income (₹1,650,780 ha⁻¹), net return (₹1,064,395.30 ha⁻¹) and benefit-cost ratio (2.82). Under the conditions of this experiment, pre-planting corm treatment with Bacillus subtilis performed better than the other tested treatments for most soil-fertility and economic indicators.