Benefit and Roles of Biochar in Environment and Agriculture

Title : Role of biochar in environmental management and agriculture

Biochar is also known by the names agrichar or the simple term, black carbon. Biochar is a charcoal-like substance produced from agriculture and forest wastes which contains 70% carbon. One of the simplest ways of making biochar is through the thermal decomposition of the biomass. Biochar can be produced through pyrolysis, gasification and hydrothermal carbonization, which leaves bio-oil and syngas as by-products. Pyrolysis involves placing the biomass into a special oven before heating in the presence of little or no oxygen. In all these processes, biomass is heated at a high temperature in the absence of air.

Benefit and roles of biochar in environment and agriculture

For environment, using biochar can slow down climate change. Carbon containing materials such as plants are made from carbon that is sourced from the air. While alive and whole that organic matter holds the carbon in place but when it burns, the carbon is released back into the atmosphere in gases like carbon dioxide. These gases then contribute to climate change and global warming. The carbon in biochar resists degradation and can hold carbon in soils for hundreds to thousands of years. By process of pyrolysis or gasification mentioned above, these help creating a soil enhancer, sustainable biochar practices can produce oil and gas byproducts that can be used as fuel, providing clean, renewable energy. Biochar and bioenergy co-production can help combat global climate change by displacing fossil fuel use and by sequestering carbon in stable soil carbon pools. This simple way can be used to reduce carbon emissions. Other byproducts of the pyrolysis process include oils and methane that can be captured and used as an environmentally friendly fuel.

In agriculture, biochar helps to improve the soil resource by increasing productivity and crop yields, reducing soil acidity, reducing the need for some chemical and fertilizer inputs and potentially providing other soil benefits.  Field trials using biochar have been conducted in the tropics over the past several years. All showed positive results on yields when biochar was applied to field soils and nutrients were managed appropriately. Biochar has the ability to improve soil fertility, leading to higher crop yields. Biochar has also been shown to reduce soil acidity. Biochar retains nutrients in soil directly through the negative charge that develops on its surfaces, and this negative charge can buffer acidity in the soil. Currently, soil acidity is corrected by applying large amount of lime. Because of biochar’s ability to enhance the availability of plant nutrients, soil nutrient retention is improved.  This means that less fertilizer needs to be applied which reduces the cost of producing the crop.

Application of biochar

Carbon sink. The burning and natural decomposition of biomass and in particular agricultural waste adds large amounts of carbon dioxide to the atmosphere. Biochar that is stable, fixed, and carbon can store large amounts of greenhouse gases in the ground for centuries, potentially reducing the growth in atmospheric greenhouse gas levels. At the same time its presence in the earth can improve water quality, increase soil fertility, raise agricultural productivity, and reduce pressure on old-growth forests. Researchers have estimated that sustainable use of biocharring could reduce the global net emissions of carbon dioxide, methane, and nitrous without endangering food security, habitat, or soil conservation.

...