The Centuries Old Practices of Producing and Applying Biochar

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Dominick Weaver
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1 The Centuries Old Practices of Producing and Applying Biochar

2 Traditional Practices for Producing Biochars; 1. Feedstock is Mixed: Manure + Wood + Leaves + Straw + Compost + Food Scraps 1. Minerals in the form of ash, shells, bone are added 2. Soil with a high clay and iron content is used to cover the pyrolysing biomass 3. Pottery or fired clay is often a component 4. Temperature of production is not uniform but can vary from around 350C-600C but mainly around 400C 5. Smoke condenses out on both the minerals and the biochar 6. Planting usually takes place 1-3 weeks after incorporation of the biochar.

3 Traditional Practices for Producing Biochars; Methods of Production 1. Pits: Australian Aborigines, some areas in Africa 2. Open fire with mixture of materials and soil (Video) 3. Soaking biomass in ponds and then using in open fire: Vietnam. 4. Mounds on land that is to be cultivated: Africa, Nepal 5. Brick Kilns: South of Vietnam used especially for rice seedling germination as well as on fields 6. Use of residuals from charcoal kilns: Europe and probably in Africa, Asia and Latin America.

2% C dating of mounds: 600 to 3500 yr old.

4 Terra Preta Australis Australian Aboriginal Cooking Oven Carbon, % C dating of mounds: 600 to 3500 yr old. Contemporary with Terra Preta soils of Amazon Carbon, 3-5% More: nitrogen calcium potassium phosphorous

Biochar is prepared during march before the rainy season 5.

5 Making Biochar in a Tamang Village in Nepal 1. History of using biochar in raising millet seedlings and growing potatoes 2. Land is very poor and each family has only.8-.9ha 3. Women mainly responsible for agriculture and for preparing the biochar. 4. Biochar is prepared during march before the rainy season 5. People believe that burning the soil increases fertility and frees it of pests 6. Use of biochar is limited by the labour available 7. So more chemical fertiliser is being used along with composted manure

6 Making Biochar in a Tamang Village in Nepal Preparing Ground Laying biomass on soil; Smouldering dung in pot next to biomass Laying smouldering dung on biomass

7 Making Biochar in a Tamang Village in Nepal Putting leaf litter on smoldering dung. Loosely covering the smoldering dung and biomass and allowing to smolder for 3 days. Temperature is low and many smoke chemicals are produced.

8 SEM Examination of Biochar From Tamang Field of Millet

9 TEM Examination of Biochar From Tamang Field of Millet. Heterogeneous at the nanoscale. High Al, Si, Fe, Ti and Ca.

Wood Vinegar an Ancient Art 1. Derived from the capture and refinement of smoke between approximately 180C-300 C especially bamboo and some hardwoods 2.

10 Wood Vinegar an Ancient Art 1. Derived from the capture and refinement of smoke between approximately 180C-300 C especially bamboo and some hardwoods 2. Allow to settle into three phases in a closed vessel and then separated. Further refinement through a biochar filter for some applications 3. Many uses but research undertake indicates that it can enhance germination, can be used as a biopesticide and a growth enhancer 4. Main constituents of phenols, alcohol acids, guaiacol, syringol, furfural, cresol 6. Different Application rates different uses. J. Major Mu et al (2003) Effect of bamboo vinegar on regulation of germination and radicle growth of seed plants J Wood Sci (2003) 49:

11 Benefits as Derived from Japanese and Chinese Research 1. Spraying diluted wood vinegar on plant leaves increases their vitality and improves crop quality. 2. Spraying also helps control harmful insects and some kinds of plant diseases. 3. Wood vinegar and agricultural chemicals are complementary. The efficacy of using them together is greater than using either one alone. J. Major Jun et al (2006) Preliminary study of application effect of bamboo vinegar on vegetable growth For. Stud. China, 2006, 8(3): 43 47; JBA Technical Manual

12 Benefits as Derived from Japanese and Chinese Research 4. If wood vinegar is applied to the soil or mixed into it in high concentrations, it inhibits eelworms and soil diseases. 5. In low concentrations or while it is in the process of being broken down in the soil it increases the quantity of useful microbes. 6. Wood vinegar helps plants develop stronger roots. 7. Mixing wood vinegar with manure reduces J. Major odours and facilitates composting. Jun et al (2006) Preliminary study of application effect of bamboo vinegar on vegetable growth For. Stud. China, 2006, 8(3): 43 47; JBA Technical Manual

Survival During The Time of Hardship in Cambodia Low

5kg rice husk, 5kg cow manure; 5 wood sticks 1.

put the wood sticks at one edge of the rice husks 3.

13 Survival During The Time of Hardship in Cambodia Low Temperature Production of Cow Dung Rice Husk; Recipe; 2.5kg rice husk, 5kg cow manure; 5 wood sticks 1. pile up the rice husk 2. put the wood sticks at one edge of the rice husks 3. light the wood stick 4. Slowly add more rice husk to fire and build up the fire 5. After about 20 minutes when fire is at maximum add cow dung

Use a fan to make sure the fire keeps on burning at a low temperature 6.

part from the burning and stop the fire by cooling on bricks or

14 Survival During The Time of Hardship in Cambodia Low Temperature Production of Cow Dung Rice Husk 4. Keep on adding the dung 5. Use a fan to make sure the fire keeps on burning at a low temperature 6. When a part of the rice husk and cow manure pile becomes biochar move part from the burning and stop the fire by cooling on bricks or covering with dirt. 7. Continue to do the same procedure until the whole pile becomes biochar.

15 Heterogeneous Particles with High N and Range of Minerals

16 Woody Biochar with range of Minerals

Ankara Method in Cameroons The farmers cut savanna grass during

year sift the soil from these beds over the piled-up grass and

The grass smoulders and forms charcoal, which is subsequently

17 Ankara Method in Cameroons The farmers cut savanna grass during the dry season pile it up between the crop beds of the previous year sift the soil from these beds over the piled-up grass and ignite the underlying grass. The grass smoulders and forms charcoal, which is subsequently mixed with the surrounding soil. At the start of the rainy season, annual crops such as maize and beans

Effects of different methods of plant residue management on soil

18 Agronomic trials Using Ankara System for Two years No Production Biochar in second year Osinamea, O. A. and F. Meppeb Effects of different methods of plant residue management on soil properties and maize yield. Communications in Soil Science and Plant Analysis 30(l&2):53 63

19 Agronomic trials Using Ankara System for Two years Aggregation of soil colloids into larger particles. The clay-sized fraction fell by 48% while the silt-sized fraction rose by 30%. Release of large amounts of phosphorus (P) and potassium (K), and trapped adequate nitrogen (N) to sustain a maize yield six times that where residues were buried under the ridges without burning and no fertilizer application, and three times that of surface burning plant residues. When no biochar the residual effects of the Ankara on a second maize crop were not significant unless fertilizer NPK was applied. Osinamea, O. A. and F. Meppeb Effects of different methods of plant residue management on soil properties and maize yield.

fire. Wood is aged underwater held down by bamboo.

20 Preprocessing of Bamboo and Wood before Making Biochar Some Vietnamese households soak their wood and bamboo in a nutrient mineral rich pond before burning in a fire. Wood is aged underwater held down by bamboo. The mineral matter that soaks into the biomass slows the combustion process and makes a large amount of biochar and ash.

The Unusual Properties of some of the Biochar made from anaerobically treated wood/bamboo Wood and Bamboo are soaked in ponds for up to 1 year before using in fire.

21 The Unusual Properties of some of the Biochar made from anaerobically treated wood/bamboo Wood and Bamboo are soaked in ponds for up to 1 year before using in fire. SEM with EDS analysis of biochar shows mineral phases rich in K Ca Mg and Si have deposited on the biomass and then reacted with the surface when heated in a fire with limited O2

22 Rice Straw Biochar has a Protective layer of Silica and other Minerals

23 Key Messages 1. Biochars and biochar-mineral mixtures made from mixed feedstocks in simple mud kilns and pits have an ash content above 10% and usually above 20%. 2. There is a high aromatic content in the carbon structure but no direct evidence of graphitic structures in the amorphous carbon phase indicating that temperatures of production were under 550C. 3. Minerals often surround the surface of the biochar. The composition and structure of the mineral phases depends on the properties of the feedstock, how they were placed in the pits/ovens/kilns and how they were fired.

24 Key Messages Key Point 2; Characterisation of Biochars Made In Indigenous Societies 1. Most biochars have a relatively high content of oxidised carbon on their surface compared with wood biochars produced at greater than 500C in a modern kiln. These functional groups arise from the low temperature of the open fires and the mounds and pits, and the reactions between the volatile gases which are being evolved from the clay, the biomass and the charring surfaces. 2. Biochars produced in earth mounds from mixed feedstock have a higher concentration of mineral phases on their surface than biochars made from a single feedstock in a steel or brick kiln. 3. All these biochars have a high concentration of very small mineral phase particles inside the carbon structure. It is probable that these nanophase particles are responsible for the improved uptake of nutrients and for changes in microbial population.

25 Key Messages Most traditional practices result in some of the smoke condensing onto the surface of the biochar and minerals. These volatile laden biochar mineral complexes are usually incorporated into the soil for a period of three weeks before crops are planted. China and Japan have had a long history of collecting the smoke from the kilns and refining it to make wood vinegar. This will be discussed in a further lecture.

26 Key Messages Biochar- mineral complexes are always incorporated for at least 3 weeks before planting. Biochar-mineral complexes are added every year before crops are planted. Different types of biochar and biochar mixes are used for different plants.

Making Biochar Commercially Viable; Recent Experiences from around the World. Stephen Joseph

Making Biochar Commercially Viable; Recent Experiences from around the World Stephen Joseph The Changing Context of The Biochar Industry 1.China with government backing is seeing a rapid growth in both