Sugarcane biomass-derived biochar for soil quality enhancement in sugarcane-growing soil

This study explored the barrel technique for biochar production, comparing it with laboratory-prepared biochar by evaluating the effect on sugarcane-growing soil quality. Different sugarcane biomass (bagasse, trash, and mini mill waste) derived biochar was prepared using a muffle furnace at three different temperatures (300, 450, and 600 °C) and with the barrel technique. Biochar was characterized by yield, pH, electrical conductivity (EC), proximate and ultimate analysis, scanning electron microscopy (SEM) analysis, and Fourier-transform infrared spectroscopy (FT-IR) characterization. A pot experiment was conducted with soil amendments with biochar (bagasse biochar pyrolyzed at 450 °C–BBC-450 and bagasse biochar prepared from barrel technique–BBC-BT) at a 2.5% (w/w) rate. The initial, 45-day, and 90-day soil samples were analyzed by selected soil chemical and physical parameters. The soil quality index of the 90-day soil samples was determined. Sugarcane biomass-derived biochar was rich in carbon content (64.68%–85.43%). Biochar amendment led to significant enhancements in soil pH, EC, organic carbon (OC), water holding capacity, total N, available P and Zn, and exchangeable K, Ca, and Mg. The results of the 90-day soil samples indicated an increase in soil OC by 1.22% due to both biochar amendments relative to the controls. Available P increased by 2.59% in BBC-BT amended soil and by 23.05% in BBC-450 amended soil. The EC increment due to soil amendments with BBC-BT and BBC-450 was 33.33% and 16.67%, respectively, in the 90-day soil samples. The highest soil quality index was observed in BBC-BT. It can be concluded that BBC-BT enhances the soil quality of sugarcane-growing soil, and the barrel technique could serve as a viable option for small-scale farmers and for domestic use in producing biochar.