Production of biochar for soil enrichment: parametric and sensitivity analysis on the yield of spinach (Maratus Calcatus)

Abstract

This thesis is based on the use of biochar for soil enrichment and its parametric and sensitivity analysis on the yield of spinach. A saw dust based biochar was used to carry out the experiment, the saw dust was dried, sorted by particle size distribution and pyrolysed at different temperatures (300°c, 350°c and 400°c) with different holding time (30 minutes, 60 minutes and 90 minutes), this was done in other to the best or optimum temperature at which a biochar with high nitrogen and carbon content could be gotten, the optimum temperature and holding time was discovered to be biochar produced at 350c at a holding time of-90 minutes. The ultimate and proximate analysis of the biochar produced at 350°c was found to have moisture content of 4.32, the ash content was 26.12, the volatile matter was discovered to be 35.32, and the fixed carbon was 34.34. The ultimate analysis result carried out showed that the carbon content was 72.45%, hydrogen was 2.66%, Oxygen present was 13.02%, the nitrogen content was 3.60% which indicated a 100% increment as compared to raw saw dust (1.41%), the biochar had no sulphur content in it(0.00%). The BET analysis indicated the biochar increased in surface area after it was subjected to pyrolysis (surface area = 591.0m2/g, pore volume = 0.1747cc, pore size = 6.077nm). The SEM analysis of the biochar was done and the scanning revealed the porous structure of the biochar and the large surface area which was essential to the retaining of nutrients in the soil. XRD revealed the amorphous nature of the biochar with its elemental composition, the FT-IR revealed the functional groups present in the biochar. A soil analysis was embarked on before the planting and after harvesting the spinach, the soil analysis clearly indicated that there was a sharp increase in the soil organic matter; phosphorus, calcium, magnesium, potassium, nitrate and the soil Ph, the parameters used in determining the yield of the spinach as compared to the control were germination time, harvest time, mass of spinach after harvesting, shoot and length of spinach. The experiment revealed the composition of biochar and organic fertilizers as a treatment prove to be more efficient in enriching the soil for better yield of the spinach.