Biochar and Your Garden

Charcoal in various forms has been used to boost soil fertility and increase crop yields for thousands of years. But one particular form of charcoal shows significant ability to increase crop yields. This is biochar.

Natural biochar—resulting from natural burning such as wild fires or human burning for ancient land clearing—can be found in soils around the world. This type of charcoal, in fact, is an important part of natural regeneration of forests, grasslands, and other wild lands.

Indigenous peoples in the Amazon basin and other areas in South America call biochar "terra preta" or black earth.

This fine-grained, highly porous charcoal [See Figure 1] improves water quality and availability to plants. It also increases your soils retention of nutrients, meaning more nutrients stay in the soil available for your plants instead of leaching into groundwater.

		Scientists have dated the biochar (terra preta) used historically in the Amazon basin. Using this data and other experiments, they estimate that biochar can remain in soil from decades to hundreds or thousands of years. What does biochar's longevity in the soil mean for you? Once incorporated into garden and farm soil, its fertility-enhancing power does not have to be maintained through further tillage. In short, biochar enhances the living conditions for all the organisms in the natural organic web of life in your soil.
Figure 1: Deceptively simple looking, biochar's physical properties enhance soil fertility by providing a slow-decomposing source of carbon while improving nutrient and water retention. Its porosity reduces nutrient leeching.

Figure 2 shows two seedlings, one germinated in regular planting soil and one germinated in biochar. Figure 3 shows corn grown in experimental plots in Bolivia. The photo on the top is corn grown in soil that wasn't enhanced with biochar. The photo on the bottom is corn grown on an adjacent plot on biochar-enhanced soil.
		Figure 2: Seedlings germinated in regular soil (left) and biochar (right).

	Figure 3: Experimental corn plots grown with and without biochar amendment

How you can become a
Biochar Environmental Warrior

Biochar has an additional benefit for you as a gardener who's concerned about the environment, greenhouse gas emissions, and even climate change. How you're able to become a "Biochar Environmental Warrior" is a fairly long discussion [click here for the whole story.

But briefly, here's how it works…

Biochar can be made from organic waste products—like rice hulls, waste from forestry product production, farming waste, animal manure, and even waste from feedlots. While a small amount of this waste is turned into compost, much of it is allowed to rot or is burned.

Treating waste this way adds a significant amount of greenhouse gases to the atmosphere—not to mention the substantial air, water, and soil pollution it causes.

Biochar production takes those (and other) waste products and heats them in an oxygen-reduced environment. When the conditions are properly controlled, biochar results. This product "locks up" carbon that would normally be pumped into the air if the waste matter were burned or allowed to rot.

When used in gardens and farms, biochar thus sequesters a large source of carbon, preventing it from entering the atmosphere. (It also helps reduce other greenhouse gases as well. See the "Biochar & Global Climate Change" page.)

But carbon-sequestering biochar isn't the only environmentally positive product that results. The production process results in combustible synthetic gases (called syn-gases or synfuels). Synfuels are currently being used in small-scale production tests to sustain the biochar production.

But they can also be used to power other energy needs as an alternative to fossil fuels.

Figure 4 shows a simplified schematic diagram of how biochar can help fight against greenhouse gas emissions.

I urge you to take a close look at the details of this remarkable process on the "Biochar & Global Climate Change" page. You can get a more complete understanding there for how you'll be able to protect your earth when you use biochar in your garden.

But here's a brief summary of the benefits of being a Biochar Environmental Warrior…

• Biochar locks up carbon in the soil that could become CO2. Sequestering carbon this way prevents this powerful greenhouse gas from being pumped into the atmosphere.
  
  
• Biochar also reduces the emission of other greenhouse gases such as nitrous oxide and methane (primarily by reducing the amount of organic waste material that's allowed to rot).
  
  
• Synfuels produced in biochar production help reduce our dependence on fossil fuels.
  
  
• Biochar increases soil fertility, reducing or eliminating the need to use artificial fertilizers and insecticides.
  
  This reduces air, water, and soil pollution from application of these products. It also decreases air pollution and carbon emissions resulting from their manufacture and distribution.
  
  
• Using biochar in your home garden lessens your dependence on agri-business. When you grow your own healthy, organic, "local" food, you reduce the use of fossil fuels necessary to grow, package, and deliver food from vast distances to your supermarket.
  
  And you reduce the immense greenhouse gas emissions resulting from wasteful agri-business practices.