Valorization of peanut shell biochar for soil amendment

Abstract

Biochar is one of the best and economical soil amendments as it helps in carbon sequestration, retains soil nutrients, increases water retention capacity of the soil, attracts more beneficial microbes and thus improves the crop yield. Peanut shell (PNB) biochar is produced by slow pyrolysis at 300 °C, 400 °C, 500 °C and 600 °C. PNB produced at these various temperatures were characterized (pH, electrical conductivity, ash and moisture content, bulk density, FTIR, SEM, XRD, SBET and elemental analyses). Pot study was carried out with soil amended with PNB obtained at various temperatures and PNB in combination with N (Nitrogen) fertilizer on sorghum crops over 30 days. It is found that Biochar increased soil water retention capacity and N fertilizer utilization efficiency by the plants. PNB, in combination with urea, had a synergistic effect that enhanced sorghum crop growth (fresh and dry weight, height of the plant, stem diameter, leaf length, leaf area). PNB showed no significant effect on seed germination. Thus, PNB, in combination with urea, can be used as an effective soil amendment technique. Highlights Biochar amendment increased the soil water holding capacity Peanut shell biochar in combination with urea has a synergistic effect Increased N fertilizer utilization efficiency by the plants when biochar and N fertilizer applied together Enhanced sorghum crop growth due to biochar amendment Application of Peanut shell biochar showed no significant effect on seed germination