Some facts about carbon!
- Low carbon in the soils leads to depleted organic carbon (OC) -
-Low OC means poor soils
-Poor soils means “food insecurity”
-Africa soils are “Carbon” deficient due to many factors- including the burning of material to “ASH”
-There is less available biomass material to burn for rural folk in Africa (about 80% rely on this as their only source of energy)!
-Biomass fuel efficiency and not “Switch of your Bulb and consume less Petrol” is the language for the rural folk, who comprise the majority of Africa population.
Traditionally, in most rural and peri-urban settings, people use biomass material to cook or heat up their homes. The biomass material used is either raw or in the form processed charcoal. This form of energy source while being widely accessible is wasteful, polluting, degrading to the environment, a health hazard and very inefficient.
Different technologies have been introduced to reduce the waste, improve efficiency and in recent times to mitigate climate change through arresting deforestation.
The concept of biochar or chracoal introduces the dimension of enhanced fuel efficiency and improved household health through the pyrolytic burning of the wood gases to provide the heat energy. Pyrolytic burning occurs under reduced oxygen and the by product is charcoal as opposed to ash. The charcoal when added to soil enhances soil fertility through primarly increasing the surface area that microbes and soil organisms. Ultimately carbon is inert (Carbon is the same material that forms Diamond)!, it is locked in the soil for a long period.
Carbon in the soil has multiple benefits compared to “switching your lights off!”, without carbon in the soil, you simply dont have food!
Soil is the third largest carbon pool on the planet. In the long term, agricultural practices that amend soil carbon from year to year through organic matter management rather than depleting it will provide productive soils that are rich in carbon and require fewer chemical inputs.
Agricultural landscape should simultaneously provide food and fiber, meet the needs of nature and biodiversity, and support viable livelihoods for people who live there. In terms of climate change, landscape and farming systems should actively absorb and store carbon in vegetation and soils, reduce emissions of methane from rice production, livestock,and burning, and reduce nitrous oxide emissions from inorganic fertilizers.
Decomposition of plant matter is one way of enriching soil carbon if it takes place securely within the soil; decomposition on the surface, on the other hand, releases carbon into the atmosphere as carbon dioxide. In the humid tropics, for example, organic matter breaks down rapidly, reducing the carbon storage benefits of organic systems. The burning of organic waste (agric waste) to ash is another reason for reduced carbon in the soils.
The option of incorporating biomass burned in a low-oxygen environment to produce energy for cooking and heating and reintroducing the char by product into the soil improves the SOC (Soil Organic Carbon), which in trun offers benefits at different levels:
Household Level Stove technology
Technology- the use of pyrolytic stoves: No noxious gases which are proven to be carcinogenic (PHPs, Aromatic polycyclic hydrocarbons etc). While the burning of biomass through pyrolysis release some carbon dioxide, majority of the carbon is left in the charcoal form in the pyrloytic chamber. This carbon-rich matter is highly stable when added to the soil.
Improved Biomass Fuel efficiency
Fuel efficiency: Less biomass material for heating and cooking needs! (Household level)
Improved Organic Carbon in Soil- means improved soil fertility
Charcoal (grinded into fine material 40-60% in char keeps carbon in soil longer and releases the nutrients slowly over a long period of time). The Carbon in the char is inert so does not get degraded. . The charcoal increases the surface area on which microbes – essential to soil fertility – simply love and multiply. A fistful of grinded char is equivalent to the size of a football pitch in terms of surface area). The microbes in turn improve the soil nutrient retention capacity, and the process is self multiplying- increased surface area means more microorganisms grow and produce even more organic matter etc. In all the char is an amendment and not a fertiliser.
- Carbon in the soil improves ground water purification
Carbon in Soil from Char
Carbon like activated carbon works by attracting and holding certain chemicals as liquids pass through it. It is a highly porous material; therefore, it has an extremely high surface area for adsorption and retention. The equivalent surface area of 1 pound of Carbon ranges from 60 to 150 acres. Char is made of tiny clusters of carbon atoms stacked upon one another. The carbon or char can be sourced from a variety of materials, such as peanut shells or any biomass material. The raw carbon source is slowly heated in the absence of air to produce a high carbon material. Pyrolysis char or carbon result has high adsorptive and adhesive properties. The physical properties of the char, such as pore size distribution and surface area; the chemical nature of the carbon source, or the amount of oxygen and hydrogen associated with it; chemical composition and concentrations of the soil minerals; the temperature and pH of the soil and the flow rate water percolatuing in the soils all affect the overall impact on the soil amelioration impact.
