Although the term “biochar” is a recent adoption, biochar is a very well known substance; it has been part of some of the best practices in traditional agriculture in different parts of the world. Farmers have used it for many purposes including soil fertility management. Recently it has attained greater importance because of ongoing scientific research and discoveries. Biochar is identified as one of the means for adaptation and mitigation for climate change.
In Andhra Pradesh, India, my project "Good Stoves and Biochar Communities" is developing new open source technologies for biochar production from crop residue and other waste biomass, and exploring methods of biochar application for improving fertility of soil and addressing carbon sequestration. We are specifically addressing the needs of the poorest farmers, to explore how biochar can help improve their livelihoods. In this article I would like to share some important lessons we have learned as a result of our experimentation, and make some recommendations for better progress.
First, biochar should not be viewed as a specialized product for soil amendment alone. As “Biocharculture” the scope of biochar is manifold. The broad areas of biochar use include soil management, livestock, biomass energy, water purification, green habitats, sanitation, health, etc. The value of biochar increases due to its reuse integrating with the above aspects where, for example, biochar used in sanitation is then re-used as a fertilizer.
There is a need for mass awareness of biochar, including the pros and cons, among various stakeholders. The main challenges are the availability of sustainable sources of biomass and the accessibility of efficient biomass-to-biochar conversion technologies.
Sustainability Must be Carefully Considered
Sustainable sources of biomass are not always available for conversion into biochar, although biomass is available from various sources in large quantities. Soil organic matter is required as a regular input for soil management, a majority of which comes from crop residue, mulch, composts, etc. In the world the amount of crop residues produced is ~4x109 Mg/year. In India alone about 800 million tones of crop residue is produced annually. For the management of crop residue there are no stringent rules. Some part of this crop residue is burnt by farmers. In the process lots of smoke is generated and the valuable biomass is wasted. But, for recommended biochar application of up to 8 to 20 tonnes per hectare, and for large scale applications by millions of farmers, presently available biomass may not be sustainable, particularly as this new demand for biochar as a soil amendment adds to the existing demands on biomass resources for feed and fuel. The approach of having captive lands for biomass production for large scale commercial production of biochar should not be encouraged, because this approach competes with the limited land resources. To import biochar from any other country is also non-sustainable and non-justifiable.
The major concern in developing countries like India is that 60 percent of the farmers live on less than one hectare of land. The farming is not sustainable for a majority of small and marginal farmers in parts of India. Over the years they have been dependent on government policies and subsidies for power, water, seeds, fertilizers, minimum support price for the produce, etc. There is a need to liberate the farmers from the dependency systems. Biochar application reduces the burden of farmers in several ways: less fertilizer is needed because biochar absorbs and slowly releases nutrients to plants; biochar improves soil moisture retention and conserves water, securing the crops against drought; farmers spend less on seeds as germination percentage increases; biochar reduces the methane emissions from paddy fields and farm yard manures; it increases the soil microbes and other soil-life density; it lessens the hardening of soils; it supports better growth of roots and helps in reclaiming degraded soils. Another advantage of biochar is that it can be used in all types of agricultural systems (organic, chemical, permaculture, mixed farming, natural farming, etc).
Biochar application in small amounts into the soil would not burden the farmer. A farmer could produce about 100 to 200 kgs of biochar from crop residue annually from one hectare of land, that would otherwise be burned in the field. This is apart from using some part of the crop residue for mulching, composting and fuel. Biochar added to soil in large quantities reduces available nutrients to the crops initially, unless it is added along with extra compost and fertilizers. But by adding biochar in small quantities the farmer need not worry much about the high costs for extra compost and fertilizers that would have been needed if large quantities of biochar are added at once. Over a period of time, biochar matures and gets adapted to the local soil conditions. Biochar will remain in the soil for more than 1000 years, so one need not be in a hurry to get maximum yields immediately.
Poor Farmers Need Open Source Biochar Production Technologies and Standards
Although farmers in our project are happy with the biochar compost application results during the field trials, it is difficult for them to adopt on a large scale because of the high cost of biochar production technologies. Because of the complexity of biomass (types, values, size, shape, density, etc.) converting into biochar is difficult by any single design, so there is a need for many different biochar production designs that are suited to specific feedstocks and project circumstances. Most of the charcoal production from wood is made by earth mound kilns, but for conversion of crop residue this technology is not convenient, and not all types of biomass are easily convertible into biochar. Presently with the traditional systems for the crop residue conversions into biochar, the efforts in procuring the biomass and converting into biochar is higher than the cost of buying the same quantity of charcoal made from wood in earth mound kilns. The technologies are also inefficient: from every 100 kgs of biomass with the existing traditional technologies on an average the yield is only 20 to 30% of biochar. Moreover, the type of biomass, process and the temperature at which the biochar is produced is important to qualify it as a biochar product.
Agriculture has become a high input and dependent system, which is hardly sustainable for small and marginal farmers. The biochar products and technologies available in the market are not accessible to farmers as they are patented and come at a high cost. Therefore the industrial approach to biochar production is not a highly feasible option in many developing and poor countries. Biochar production technology designs for small farmers should be cheap, efficient, mobile and convenient for in-situ production.
Having found a new opportunity in biochar, many private companies have emerged to sell it as a product. Companies are doing research on biochar compounds and they are publishing the results of the product application on crops. The results are very encouraging. But the ingredients of biochar products that are available are often proprietary and not divulged. The efforts of all the companies and organizations involved in research should be compensated by either national or international agencies, and the components of biochar products should be revealed in the common interest. The biochar products (blends) being promoted in different names by various companies are very confusing. There is a need to standardize the biochar products for application to different types of soils and crops in different geographic regions and conditions.
Recommendations for Moving Forward
Integrating biochar production and application locally is likely to be a more sustainable practice than large scale centralized production and dissemination. There is a need for greater research and development on biochar. All the biochar production technologies and application techniques should be under open knowledge. Large scale awareness of the pros and cons of biochar production and application should be created. And also ongoing traditional biochar practices should be recognized and improved.
Some of the immediate actions required are:
Study all of the traditional biochar/Terra Preta practices in different parts of the world. We need to find ways to improve these existing practices for sustainability and adoption. While facilitating the low-cost efficient adoptable technologies for conversion of biomass into biochar, stringent laws can be brought to prevent open burning of crop residue. Inefficient biochar production technologies should be replaced in a phased manner. All the biochar technologies should be declared as open knowledge, and the people or agencies invested in developing such technologies should be compensated. Similarly all the biochar products/blends should be made open along with the results. Standardization of terms should be made by a common agency. Biochar as a byproduct should be given top priority for usage, rather than producing biochar exclusively. There are many sources, including stoves, gasifiers, biomass to energy etc. that can produce both biochar and energy. In-situ biochar production and application should be encouraged and given top priority.
Dr. Sai Bhaskar Reddy Nakka is the Founder and CEO of Geoecology Energy Organisation [GEO], an initiative to mitigate climate change through adaptation. Dr. Sai has a double masters in Applied Geology and Geography from Indian Institute of Technology. For his PhD he pursued “Environmental Impact Assessment (EIA) Studies of the Polluted Water at Patancheru Industrial Area, Medak Dist., A.P., India. He is also a qualified as CDM/Lead Verifier, and a specialist of Information Visualization and Graphics, GIS/RS, ICTs, and Participatory Monitoring tools.