Impact of Rice Husk Biochar on Soil Carbon Sequestration, Methane Emission, and Rice Yield in Wetland Soil (Ultisol)

Abstract

The integration of physical, chemical, and biological indicators of soil quality that have an impact on environmental factors and farmer profitability is the focus of soil health. Applying biochar is an effective technique to promote soil carbon sequestration, which is a component of soil quality. Rice husk biochar (RHB), produced from the pyrolysis of rice husk (RH), has a higher nutritious value than biochar made from wood. A field research was conducted to evaluate the short-term implications of RHB-derived nutrient translocation and distribution in rice crop, as well as their effects on soil nutrients, rice productivity, and methane (CH4) emissions in wetland Ultisol. The treatments included applying four organic fertilizers: rice husk biochar, daincha (Sesbania aculeata), jack tree (Artocarpus heterophyllus) leaves, and farm yard manure (FYM) at rates of 35 (N1), 70 (N2), and 105 (N3) kg N ha−1. The results showed that the application of RHB enhanced the uptake of soil organic carbon (SOC) as well as the production of rice grains and straw. The yield of brown rice increased with higher rates of N treatment. The RHB contributed a significant amount of carbon to the refractory paddy soil, which increased its carbon content in the crop as well. Consequently, there was a significant 50–60% drop in CH4 emissions from soil as compared to FYM.