Evaluation of vesicular-arbuscular mycorrhiza and organic amendments for improving growth and yield of chilli (Capsicum annuum L. cv. Priyanka) in compacted clay soil

Abstract

Clay soil with high bulk density is a major physical constraint that limits root growth, water infiltration, aeration and nutrient uptake, ultimately reducing crop productivity in the study area. This study evaluated the effectiveness of vermicompost, paddy husk, cocopeat and arbuscular mycorrhizal fungi (AMF) in reducing the bulk density of clay soil and improving soil physical properties under chilli (Capsicum annuum L.) cultivation. A pot experiment was conducted using different treatment combinations of these organic amendments and AMF. After the cropping period, soil bulk density, porosity, moisture retention, root colonisation and plant growth parameters were assessed. The combined application of vermicompost, cocopeat, paddy husk and AMF significantly reduced soil bulk density compared with the untreated control and increased soil porosity, water-holding capacity and root development. Enhanced AMF colonisation further improved nutrient uptake and promoted plant growth through better soil aggregation and root-soil interactions. Among the treatments, the integrated application of all three organic amendments with AMF produced the greatest improvement in soil physical properties and chilli growth. The results demonstrate that the synergistic use of vermicompost, paddy husk and mycorrhiza offer an effective and sustainable strategy for alleviating soil compaction, restoring soil health and enhancing crop productivity. This integrated approach has considerable potential for improving the management of compacted agricultural soils while reducing dependence on synthetic soil conditioners.