This research addresses two urgent problems in developing country contexts. The first of these is the loss of productivity of smallholder agro-ecosystems associated with fuelwood harvest as well as the degradation of soil carbon, beneficial microbial communities, and nutrient cycling in soils. The second is the negative human health impacts of existing uses of biomass fuels in rural households of developing countries.

Sub-Saharan Africa remains the area with the highest rate of food insecurity (Ahmed et al., 2007). Africa’s food insecurity is directly related to insufficient total food production (Sanchez, 2002), and the rapid increase in soil degradation is the primary threat to agricultural productivity in Africa (Lal, 2006). Soil degradation is set in motion primarily when forests and grasslands are cleared for agriculture (Solomon et al., 2007) and by the need to cultivate marginal lands to increase food production. Initially, farmers see an increase in agricultural productivity as native soil organic matter is mineralized and nutrients are released. However, constant cultivation, without returns of organic matter (e.g., crop residues) or nutrients to the soil, rapidly leads to reduced crop productivity (Kimetu et al., 2008; Ngoze et al., 2008). Reduced soil organic matter and plant productivity can lead to an impoverished soil microbial community in which beneficial plant-microbial symbioses such as those with mycorrhizae and beneficial bacteria in the root zone are impaired in their ability to promote crop growth. We hypothesize that biochar as a microbial inoculant carrier and soil amendment may produce beneficial shifts in microbial communities and nutrient cycling that will stabilize or reverse soil degradation processes.

Unsustainable agricultural practices are not the only causes of soil degradation. Rural households in most developing countries depend on biomass as a source of energy.  Most of it comes from woody biomass, either used as firewood or charcoal for cooking (Okello et al., 2001; Wamukonya, 1995). Although individual households may harvest wood from their own farmland or gather dead wood from protected lands, the main source of wood for charcoal making comes from the forest (Vajpeyi et al., 2001).  It is estimated that, in Africa, losses of 5 million ha of forest occur annually. In comparison to three-stone fires or traditional cookstoves, biochar producing pyrolysis cookstoves we will be developing could simultaneously provide a sustainable source of inoculant carrier material and also reduce pressure on woody biomass resources, by using a wider range of fuels from crop residues or other vegetation..

In addition to soil degradation there are serious adverse health effects from the use of biomass fuels in traditional cook stoves or ‘three stone fires’ from poor indoor air quality. About half of the world’s population, 3.2 billion people, still relies on coal and biomass fuels, such as wood, dung and crop residues to satisfy basic energy needs (Rehfuess et al., 2006). Indoor air pollution from burning these solid fuels on open fires or in traditional stoves is responsible for 1.5 million deaths every year (World Health Organization, 2006). Women and children are the most affected, since they spend the most time in the kitchen. In fact, indoor air pollution from inefficient household stoves has been causally linked to acute lower respiratory infections (Smith et al., 2008), the leading cause of mortality globally in children under 5 years of age. We expect that a next-generation clean burning pyrolysis cookstove can reduce smoke and other pollutant emissions to levels that would provide dramatic impacts on maternal-child health.