Comparative study on the application of compost, sawdust and cow dung biomass for the sustainability and improvement of soil nutrients in Nigeria

Biochar can be used as soil amendment to improve crop growth. The production of biochar through pyrolysis and the composting process of Cow Dung and Sawdust were carried out, and the resulting products were characterized using Fourier Transform Infrared Spectroscopy (FTIR, Spectrum), proximate analysis, and physicochemical analysis. The determination of heavy metal concentrations was carried out using an Atomic Absorption Spectrophotometer (AAS, PerkinElmer 800). Results were compared with WHO and USEPA standard for soil quality and analyzed using descriptive and one-way ANOVA statistical analysis. The results obtained for proximate analysis; volatile matter gave mean values of 24.00–55.00% for Compost (CP), Sawdust biochar (SDB) and Cow Dung biochar (CDB); moisture content (%) gave 10.94 ± 1.00 for CP, 1.65 ± 0.01 (SDB) and 1.18 ± 0.01for CDB; Ash content (%) gave 5.40 ± 0.02 (CP), 7.80 ± 0.02 (SDB) and 9.20 ± 0.01 (CDB), and Fixed carbon content of 39.60 ± 0.02 for CP, 68.50 ± 0.01 (SDB) and 67.60 ± 0.02 for CDB. Heavy metal concentrations showed mean values ranging from 0.00 to 0.04 mg/kg (Zn, Pb, Cd, and Cr) for CP, SDB, and CDB, which were within the WHO and USEPA standards for soil health. The minerals present in biochar, compost and sand (control) gave mean values of nitrogen (%) ranging from 0.02 to 0.17 for CP, SDB, CDB, and Sand (control), and other parameters (mg/kg) gave 8.26–12.54 for Phosphorus and 375.36–461.36 (Potassium). The biological tests of different pots experimental design improved the growth of maize plant. The uptake of nutrients in CP, CDB, and SDB by maize plant is an indication that, there are nutrients availability in the samples which enriched the plant and soil nutrients. The nutrient uptake was highest in CDB, followed by CP and SDB. The highest in height of plant growth was seen in SDB. The values analyzed showed a significant difference at ( P < 0.05). The obtained results indicated that both the biochar and compost derived from Cow Dung and Sawdust possess valuable properties that can positively influence soil health. This research highlights the potential of utilizing biomass waste to create sustainable soil amendments, providing alternative solution to synthetic fertilizers for agricultural practices.