Valorising Pig Manure into Sustainable Biochar for Soil Enhancement and Carbon Sequestration Applications

In this study, we examined the pyrolysis of pig manure (PM) wastes into biochar manure (BCM) for potential applications in enhancing soil structure, nutrient cycling, and carbon sequestration. PM-BCM was synthesised through pyrolysis in a batch-operated drum kiln pyrolyser at a temperature of 600 °C for 30 minutes of residence/holding time. Next, the PM-BCM was characterised to examine its physicochemical properties and utility potentials based on the following parameters: pH, total dissolved solids (TDS), oxidation–reduction potential (ORP), salinity (SAL), electrical conductivity (EC), and density (ρ). The results revealed the values pH 8.34, TDS 184.02 mg/L, ORP 126 mV SAL 149.33, EC 301.67 μS/cm, and ρ 1,144 kg/m³. Results showed that PM-BCM displays an alkaline pH, which could assist in neutralising acidity whilst boosting the soil microbial activities. EC and TDS revealed functional but balanced mineral ion contents suitable for enriching soils. ORP revealed that PM-BCM exhibits oxidative characteristics that could impact nutrient accessibility and microbial processes in soil systems, whereas SAL revealed controlled salt content. Moreover, the compact nature of the BCM, observed in its high density, indicates the potential for extended soil stability, sequestering carbon, and gradual nutrient delivery. Overall, the study reveals that PM-BCM is a low-cost, sustainable, and effective candidate for soil enhancement application.