Date of this Version
Uwase, A. 2022. Biochar: Properties and Potential Benefits for Agricultural Soil in Rwanda. Undergraduate Honors Thesis, University of Nebraska-Lincoln.
Physical and chemical soil degradation is becoming a major challenge for agricultural productivity in Rwanda, which is the most important part of the country’s economy. The wide spreading soil degradation in Rwanda is mainly a result of naturally poor soils coupled with unsustainable soil management leading to, for example, accelerated soil erosion, acidification, nutrient loss, compaction, and to decreasing yields. Biochar, as an end product of pyrolysis of biomass in the absence of oxygen, has been proposed as a soil amendment in remediation strategies because of its positive effects on soil productivity relevant parameters such as soil pH, structure, nutrient retention, water holding capacity, and carbon storage. This thesis reviews existing scientific literature on Rwanda's soil characteristics, biochar properties, different types of biochar feedstock specific to Rwanda, and potential benefits of biochar application to the soil in Rwanda. Because there are no published data on biochar application in Rwanda's soil, biochar data from soils with similar properties to soil in Rwanda were used. Biochar production strategies were also reviewed including large-scale production, mainly used in industries, and small-scale production, primarily used on farms. The thesis revealed that temperature and type of feedstock used in biochar production are among the most crucial parameters that determine the properties of produced biochar. High pyrolysis temperature promotes biochar production with high porosity, organic carbon content and pH. biochar produced from solid wastes and animal manure feedstock exhibit properties with high CEC and low carbon content while biochar produced from wood and crop residue exhibit properties of high carbon content, surface area and porosity The research clearly showed that biochar application improved soil with similar properties and fertility issues to soil in Rwanda and that biochar produced with feedstock widely available in Rwanda would have ideal properties, hence increasing crop yield when apply to the soil.