Appraisal of Dual-mode Application of Potassium Solubilizing Bacteria (Bacillus amyloliquefaciens) in K-rich Sandy Loam Soil: Insights from Sweet Corn

Abstract

An experiment was undertaken during the winter season (November, 2022–February, 2023) at the college farm of the Professor Jayashankar Telangana Agricultural University (PJTAU), Rajendranagar, Hyderabad, India.  In this study, dual-mode application of potassium (K) solubilizing and plant growth promoting bacteria (KSB) strain Bacillus amyloliquefaciens was used to substitute chemical K-fertilizer for high K demanding sweet corn, in K-rich sandy loam soil to improve sweet corn yield, quality and profitability. Overreliance on chemical fertilizers in agriculture jeopardized human, plant, and soil health, leading to deterioration of agricultural productivity and soil functions despite continued fertilizer use. Hence, integrated use of chemical and biofertilizers may address these problems. Present experiment showed non-significant differences in plant performance up to knee-height stage (30 DAS). However, complete avoidance of recommended chemical-K (RDK₀)±KSB was inferior to other treatments. From 60 DAS onward, significantly higher leaf area and biomass accumulation plant^-1 were recorded with all 100% RDK (basal or split application)±KSB treatments and 75% RDK+KSB. Consequently, 30.5–19.2% higher green cob yield, 27.4–16.76% higher stover yield, and 49.6–28.6% higher net returns were observed, along with increased total soluble solids, N and K content, and crude protein in kernels compared to 0% RDK. However, kernel and fodder P content was significantly higher with KSB application irrespective of fertilizer dose. Crop growth rate significantly varied from knee-height to tasseling stage, while micronutrient content in kernels remained unaffected. Thus, KSB substituted recommended potassium fertilizer dose by 25% without compromising crop performance and sweet corn quality.