Biocharculture Biochar for Environment and Development

Preface

Here is a question often asked with great concern: can agriculture meet the challenges of an expanding world and a global economy that is moving more to ‘middle income’? The projections by the Food and Agricultural Organization for instance are that by 2050 the demand for food and fibres - compared with 2005 - will have expanded by 60% respectively 81%. Is this a challenge that is too hard to meet?

A recent comprehensive review of co-optimizing solution for food, water and energy by the World Business Council for Sustainable Development found that we still have many co-optimizing options in hand, but it also means that we need to rejuvenate the way farming is done. Agriculture needs to be more precise. It needs to be better integrated in the landscapes that it is part of and it should be supporting rather than substituting natural processes.

It is in this regard that I am very happy to introduce this book on Biocharculture and also to acknowledge its unfailing energetic author, Sai Bhaskar Reddy. We are happy that much of his overall insights and first hand experiences have become available through this book.

Biocharculture falls very much in a vision of an agriculture that supports and makes use of natural growing mechanism. Biochar is charcoal that is used for other purposes than heating. It can be a by-product or part of an entire production system.

Biochar scores on many fronts: it improves the capacity of the soil to retain moisture but also nutrients, such as nitrogen and phosphorus. It helps regulate soil temperature and contribute to climate change mitigation. It improves soil life. I still remember that Sai Bhaskar explained a tiny piece of charcoal to me as being a ‘skyscraper for millions of soil biota’. There is still a world to gain – by better understanding this miraculous microbial world and the way our soils and landscapes work and this book hopes to contribute and give practical suggestions and directions. Interesting in some parts of the world biochar is part of the production process where in other it is not. In other words, we need to create new traditions and farming cultures, as this book very much argues.

Frank van Steenbergen

Director, MetaMeta

Paardskerkhofweg 14

5223 AJ 's-Hertogenbosch

The Netherlands

www.metameta.nl

Introduction

Biochar research inspired the development of a revolutionary technology that can have tremendous impact on agriculture, water, habitats, energy, health, sanitation, livelihoods, environment, and carbon sequestration. This book contributes to the understanding of biochar as a resource. Although the term biochar has only recently been adopted, it is a very well-known concept. Biochar has long been part of some of the best practices in traditional agriculture in different parts of the world. People have used it for many purposes, including soil fertility management. Recently, biochar has attained greater importance as a result of discoveries about biochar use in the past and ongoing scientific research about its characteristics.

Picture: A fresh piece of biochar

This book highlights the diverse uses of biochar. Biochar is a traditional, cultural, sustainable, and adaptable practice and is not just a product for soil amendment. The term 'Biocharculture' was coined by the author.

The application of biochar to soil enhances its fertility and enables long-term carbon sequestration. And also offering an innovative opportunity to enhance the living conditions of rural families. Additionally, these effects counteract deforestation, protect biodiversity, increase crop production, improve agricultural waste management, and remove carbon from the atmosphere—functions that are crucial to a carbon-negative strategy to fight global warming.

Common substances like soil microbes, pottery shards, bones, urine, mulch, compost, manure, and silt used to be integral parts of biochar. In the recent past, these were replaced by non-disclosed elements.

Biochar is sold as a commercial product under different names, generating some confusion about the substance. It would be difficult for biochar to become a culture like Terra Preta unless pragmatic practices are evolved to adapt to the present context.

~ Biocharculture is a holistic approach that has been historically tested, traditionally practiced, is culturally integral, economically viable, socially responsible, environmentally sustainable, and agreeable as a policy. ~

Background

Biochar is produced after pyrolysis of biomass, typically within a temperature range of 300°C to 800°C (Barnikv). Biochar formed within this range is the most valuable. At relatively lower temperatures, a higher percentage of the biomass gets converted into biochar. At higher temperatures, some part of the biomass is converted into energy, producing less quantity of biochar. As such, the design of the pyrolysis kiln or retort is important in determining temperature range and biomass to biochar conversion efficiency.

In rural areas where biochar is simply the end-product left behind after meals have been prepared on biomass stoves. Stove design determines the rate of energy generated, biochar and ash produced as by-products. The author has designed over 50 biomass cook stoves based on materials available in rural sites. With its higher efficiency, a typical ‘good stove’ reduces biomass fuel consumption and produces 16% to 25% biochar of the original biomass used as fuel by weight.

Research has shown that the benefits of biochar include improvement in soil productivity, long-term soil carbon sequestration, reduction in greenhouse gas (GHG) emissions, and reduction in loss of nutrients by leaching (Lehmann et al., 2006). Biochar is known to have high cation and anion exchange capacity (CEC and AEC respectively) and adsorption and absorption, which improves nutrient use efficiency when biochar is applied to the soil. Biochar is particularly beneficial in sandy soils and highly weathered clay soils with low native CEC and AEC and low fertility. Biochar also acts as a source of small amounts of P, K, and other nutrients (Lehmann et al., 2003; Lehmann et al., 2002). Soil pH is an important factor in determining the bioavailability of nutrients, and biochar is known to raise soil pH (Chan et al., 2008), thereby improving the availability of nutrients to crop plants. Biochar compost has a very high soil microbial density, which balances and brings the soil pH close to neutral over a period of time. Biochar compost can be applied to all types of soils, i.e., acidic, basic, and neutral soils. It has been reported to adsorb harmful chemical compounds from the soil, such as phytotoxins and nitrification inhibitors, and improve plant growth. Biochar is also reported to enhance the microbial population (Wardle et al., 1998; Zackrisson et al., 1996), and improve moisture holding capacity and soil structure (Piccolo & Mbagwu, 1990; Piccolo et al., 1996).

In the wake of rising carbon dioxide concentrations in the atmosphere and global climate change (IPCC, 2007), biochar’s resistance to decomposition offers another ecological benefit. Biochar can remain in soil for extensive periods of time—from hundreds of years to millennia (Cheng et al., 2008; Saldarriaga & West, 1986). Glaser (2001) has reported that the Terra Preta soils contain up to 70 times more carbon than neighbouring soils. Radiocarbon dating of these soils show biochar dating back from 740 to 2,460 years (Saldarriaga & West, 1986). Research has shown reductions in GHG emissions (Singh et al., 2010; Spokas and Reicosk, 2009) and reduced losses of nutrients due to leaching (Laird et al., 2010) when biochar is used as a soil amendment, which adds further incentive for its use.

Definitions

The science of biochar is still emerging, so there is no single definition for the term. Biochar is another name for charcoal used for particular purposes other than combustion. Like all charcoal, biochar is created by the pyrolysis of biomass. Biochar’s typical physical and chemical composition allows beneficial application in a variety of sectors. The following statements provide clarification:

- The term biochar is used mainly in the context of soil fertility enhancement and management

- The prefix ‘bio’ in biochar implies living, i.e., the microbial life in the ‘char’.

- Biochar is the charcoal (carbonaceous material) produced from biomass for good use.

- Biochar is produced from biomass at temperatures between 300 to 800 degrees centigrade. Biochar produced as a by-product in biomass cook stoves falls within this temperature range. The biochar produced at temperatures above 800 degrees centigrade or below 300 degrees centigrade can also be used for various purposes, but it is much less effective.

- The uses of biochar—as part of biocharculture—include its application in the areas of soil management, livestock, biomass energy, water purification, green habitats, sanitation, food, health, etc.

- As a geoengineering process, application of biochar addresses environmental and livelihood issues of communities. A porous material, biochar increases water retention, stimulates symbiotic nitrogen fixation in legumes, and creates a cosy home for bacteria, micro-organisms, fungi, minerals, and nutrients in general. This leads to improved nutrient supply for plants and reduced nutrient losses due to leaching (Glaser, 2002).

- Biochar, as a relatively stable form of carbon, is still found in ancient Terra Preta soils of the Amazon Basin, and thus could be considered as a long-term carbon sink (Lehmann, 2007).

Picture: Left - a nutrient-poor oxisol; right - an oxisol transformed into fertile terra preta using biochar.

Biocharculture

Biochar definitions are evolving; some are limited to explaining its use for soil amendment. In this book, the idea of biochar