Sustainable utilization of biochar and compost using chicken excreta and groundnut shell to enhance soil nutrients and plants growth in Northeast, Nigeria

Biochar has improved soil fertility and crop productivity in various agricultural and industrial activities. This study assesses the application and characterization of biochar and compost derived from chicken excreta (CEB) and groundnut shells (GSB), evaluating their potential to enhance soil nutrient content and support sustainable agriculture. Collected samples were analyzed for proximate, heavy metals, and physicochemical parameters using FTIR and AAS. Results were analyzed using descriptive and two-way ANOVA statistical analysis for SPSS, and were compared with the WHO and USEPA set standards for soil quality. The obtained results for CEB, GSB and CP gave mean values (%) ranging from 1.13 ± 0.01-3.53 ± 0.01 for moisture content, volatile matter (2.10 ± 0.10-46.01 ± 0.01), ash content (6.18 ± 0.01-11.50 ± 0.05) and fixed carbon (46.77 ± 0.01-85.33 ± 0.00) for proximate analysis, physicochemical parameters gave 8.45 ± 0.01-9.35 ± 0.01 for pH, cation exchange capacity (5.33 ± 0.01-6.33 ± 0.01%) and organic carbon (5.97 ± 0.01-6.26 ± 0.01%), heavy metals gave 0.00±0.00-20.72±0.00 mg/kg for Zn, Cr, Pb and Cd for CP, CEB and GSB, and were significantly different at (p < 0.05). Results obtained were below the set standards by the WHO and USEPA for heavy metal concentration in soil for plant growth. The results demonstrated distinct properties of biochar derived from chicken excreta, groundnut shell, and composted biomass. Biochar exhibited lower moisture and volatile matter, and higher fixed carbon content, indicating its stability and suitability for long-term storage, suggesting its potential for carbon sequestration. In conclusion, essential mineral content (Nitrogen, Phosphorus, Potassium, Sodium, Calcium, and Magnesium) found in biochar and compost highlighted their potential to improve soil fertility, thereby providing a sustainable alternative to synthetic fertilizers in agricultural applications.