CSA, Biochar & Agroforestry
Climate Smart Agriculture (CSA) is a suite of low cost, sustainable agricultural practices recognized for contributing to soil health and improved agricultural productivity as well as for ameliorating environmental problems, such as water pollution, water scarcity and climate change. While the production and use of biochar is part of the CSA solution, it is underutilized compared to other techniques.
Biochar production, a 2,000-year-old practice that converts agricultural waste into a soil enhancer, involves heating biomass with little or no oxygen to drive off volatile gasses, leaving Carbon behind. Waste materials appropriate for biochar production include crop residues (both field residues and processing residues such as nut shells, fruit pits, and bagasse) and some invasive species such as tifa and elephant grass, as well as yard, food, and forestry wastes, and animal manures.
When used as a soil amendment, biochar alters the property of the soil, enabling it to retain more water and nutrients, attracting microbes and allowing plants to fix atmospheric nitrogen more efficiently and attracting microbes. Especially when combined with natural fertilizer such as manure, ground animal bones and compost, this improves plant growth and resilience.
Biochar has been demonstrated in many small pilot projects in Sub Saharan Africa to significantly increase soil productivity and water retention and to sequester carbon, especially in highly weathered tropical soil. While results vary depending on materials used to make the biochar, the soil and crop type, the co-compost fertilizer materials and climatic conditions, biochar increases productivity on average by 25% in tropical regions and 80% if nutrient-rich feed stocks are used to make the biochar. If the soil is of extremely poor quality to begin with, the productivity increase can be significantly greater, with 100% to 500% yield increases.
Planting high-value perennial tree crops in combination with the use of biochar will pull additional carbon out of the air to be stored in above-ground biomass and in root systems that also contribute to soil health. The sale of the perennial crops as well as the increase in productivity resulting from biochar and natural fertilizer use will generate revenue.
An article in the December 6, 2018 issue of Nature underlines the importance of using biochar in order to meet the Paris climate pledges. Low tech biochar producing stoves, where the heat generated is used as clean, renewable energy for cooking, have been demonstrated in many locations in Africa.
Today’s biochar pyrolysis technologies can be greenhouse gas negative, and the heat or/and a combustible gas can be recovered to simultaneously generate renewable energy or electricity serving micro grids or even larger industrial systems.