Synergistic Effects of Coconut Frond Biochar and Liming Materials on Physical Properties of Laterite Soils

Abstract

Background: Biochar is a carbon-rich material produced through the thermochemical decomposition of biomass under oxygen-limited conditions. It improves soil physical properties by improving porosity, water retention, and aggregate stability, while also contributing to long-term carbon sequestration. Liming enhances soil physical, chemical, and biological properties by improving soil structure, increasing pH, reducing aluminium toxicity, and promoting microbial activity, thereby creating a more favourable environment for plant growth and nutrient availability. Aims: The study aimed to explore synergistic effects of coconut frond biochar and liming materials on physical properties of laterite soils at Kerala, India. Methodology: The study was conducted at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala Agricultural University, India, between June 2023 and September 2023. The treatments included CFB at 10 t ha-1 with CS as LR, CFB at 10 t ha-1 with dolomite as per LR, each in combination with NPK as per KAU package of practices (KAU POP) recommendation, KAU POP (FYM at 20 t ha-1 + 75:40:25 kg NPK ha-1 + lime at 500 kg ha-1), KAU organic POP (FYM at 25 t ha-1 + poultry manure (PM) at 1 t ha-1+ lime at 500 kg ha-1) and an absolute control. Results: Application of CFB at 10 t ha-1 with dolomite or CS as per LR significantly improved soil physical properties compared to KAU POP and KAU organic POP. Compared to KAU POP, CFB-based treatments reduced bulk density up to 7.3, 3.47 and 0.68%, increased porosity up to 16.94, 6.35 and 5.33%, improved water stable aggregates up to 8.55, 13.81 and 19.13%, and enhanced water holding capacity up to 41.94, 23.94 and 19.53% at soil depths of 0-15,15-30 and 30-60 cm, respectively. The CFB-based treatments showed similar improvements compared to KAU organic POP also. Conclusion: These results indicate that integrating CFB with liming materials can effectively enhance soil structure, moisture retention, and overall soil health in laterite soils, making it a recommended practice for farmers to improve crop productivity and long-term agricultural sustainability. Overall, this study underscores the potential of biochar-based amendments in enhancing soil physical properties, thereby contributing to sustainable soil management and improved crop productivity in acidic soils.