Africa

Invader Bush Namibia
Tom Miles, August 2008

Thorn bush is one of many invading bush species in Southern Africa. This bush is currently made into charcoal and in one location cleared to preserve habitat. The photo above is from the Chameleon Bush Encroachment Wiki created to help resource managers control the bush. Highlight the photo to see an album of photos showing the invader bush and chips recovered from clearing.

Principal species shown are sicklebush (Dichrostachys cinerea), blacktorn (Acacia mellifera), Mopane (Colophospermum mopane). Other principal species are yellow bark acacia (Acacia erubescens), red thorn or false umbrella thorn (Acacia reficiens),and to the South, three thorn Rhigozum (Rhigozum trichotomum).

There are hazards in the bush including the black mamba, or Shadow of Death, that struck us on the way to the Cheetah Conservation Fund (CCF) reserve. The beneficiaries of clearing the invader bush are the animals and, of course, the livestock which has lost both value from damaged hides and pasture.

Tom

Jatta Charcoal Retort, The Gambia
Bakary Jatta, Bwiam Villiage, The Gambia, March 27,2008
Jatta Retort

My retort is in my back yard. It is a drum with a fairly tight lid and a piece of pipe letting volatile gasses take over the initial firing in the firebox underneath. The drum is enclosed in a rock and soil and lime plaster wall. For a quick start I surrounded the drum with small branches or crop waste before covering the top with a scrap iron sheet with a gap for smoke to escape in the beginning. The drum costs money, the rest is labor.

The biomass is crop waste and or tree trimmings. Some material is up to 50 mm thick and still chars all through. Like was stated on the list, the char appears to be about 40 %. After initial smoke, the volatiles take over and burn with a roaring sound. Sorry, no analysis of the off gasses, but I trust I am not a poluter beyond the normal CO2. With adequate investment the excess gas or heat can be utilized, not likely an easy option for most third world farmers.

Where does all the biomass come from? Plant it! People still get rid of lots of it to clear roadsides and farms here. OTOH, I am planting more biomass every year and my soil is improving in the process. My mini climate is improving too as many of the trees retain their leaves during the dry season . Jatropha curcass is a soil improver and wind break. Not useful for char, but it makes great fuel oil for lamps and soap making. The oil cake makes good methane gas for cooking. The digester effluent is mixed with the bio char before it put in the planting holes on the field. Soil improver, energy and soil micro-organism inoculant.

Is it economic? What is the meaning of that? Maybe, when I get a good harvest, which depends on many other factors, like rain, etc. After all, food prices are going up because of increasing scarcity. Maybe some people think they can eat their economic gain in the form of money. During the last world war money could not buy food that was not there! You think the government is going to regulate food production to assure economic gain and sustainability? Or the market place will be regulating the climate in a timely fashion so that harvests will be reliable. My conclusion is that the real value is the food and other resources provided by the life of the plant springing from the soil.

Why am I doing this? I think it is a usefull thing to do. There was a quotation that I recognized as true: 'The Spritual precedes the material'

The economic consideration will not bring a solution. It has in fact been the cause of the problem!

So, considering economic criteria, maybe no present value seen yet , but the net value will be having a future worth having at all. It is a choice and it better be a collective choice. If it does not do all as expected, do we lose anything?

Kind regards,

Bakary Jatta

Bwiam village, WR

The Gambia

Virtual Academy for the Semi-Arid Tropics (VASAT) http://www.vasat.org/

VASAT Wiki

Microcatchment Rainwater Harvesting Systems: Zai Planting Holes Section 2.1
Olufunke Cofie, Boubacar Barry, Deborah Bossio, International Water Management Institute, Ghana and Sri Lanka, Nobember 22-25, 2004

[img_assist|nid=391|title=Zai Planting pit, Sandy Soil, Niger|desc=|link=node|align=left|width=400|height=293]

"Human Resources as a driver of Bright Spots: the case of rainwater harvesting in West Africa", Conference Paper 19, NEPAD/IGAD Regional Conference: Agricultural Successes in the Greater Horn of Africa, Nairobi 22-25, 2004

2.1 Micro-catchment rainwater harvesting systems

"There are many types including: terraces, earth or rock bunds, tied ridges, rock dikes, stone lines, planting pits or basins and their modifications used in different parts of West Africa. Stone and earth bunds have been used for several years to trap water for crops during the rainy season. Around Upper West Region in Ghana, these bunds have been developed into a terrace system on the slopes. The bunds are square, or rectangular shape, and their slopes are not along the contour. Millet is the main crop grown under this system in Ghana. The height of the stone bunds depends on available stone or soil depth in the neighborhood. In some places stone lines are used. These are made up of continuous lines of stones in a field along the contour to slow down the flow of rainwater, thus enhancing infiltration and to facilitate to some extent the deposition of vegetable debris and fine soil particles which increase soil fertility in the long run. Planting Pit or Basin is commonly used in the sub-region with various modifications including the zai in Burkina and in Mali, and also Tassa and half moon in Niger. In Ghana, stones are removed to create pits for collection of water in areas with high clay content in the subsoil (Kranjac-Berisavljevic et al 2002).

Perhaps the most sucessful of these techniques is the zai ("water pocket") in Burkina Faso Zai is an ancestral planting pit developed in the Yatenga province, North Western part of Burkina Faso (where average rainfall is about 600 mm, with recurrent droughts and where soils are heavily encrusted. The Yatenga province has a hig population density (80 hbts/km2), and sufferred from recurrent droughts in the late 1960's and early 1970's. Since the early 1980's, "zai" has been rapidly revived and adopted by farmers, resulting in 1989, over 8000 hectares of degraded land in over 400 vilages in Burkina, being brought back to productivity. Large areas of the province are covered with lateritic soils of low infiltration capacity. the objective of the Zai practice is to regenerate the most degraded part of the field. It consists of digging holes or 'basins' of around 20-20 cm in diameter and 10-15 cm in depth. (Bandre and batta, 2002). The holes store rainwater, for plant growth. Generally the density is about 10,000-15,000 holes/ha depending on the crop chosen and the spacing between holes. Farmers use stone contour bunds to reduce the speed of runoff allowing infiltration into the zai which collect and concentrate the runoff. The larger the planting pits, and the bigger the spacing, the more water can be harveted from the uncultivated micro-catchments. Organic manure is put in the holes at a rate of about 3-4 t/ha. Sorghum is the preferred crop because of its greater adaptation to possible temporary hydromorphic conditions in the hole.

According to Fatondji (2002) working in Naimey (Niger), the Zai technique assured a substantial total dry matter (TDM) increase (3086 kg ha-1) compared to flat planting (991 kg ha-1) with cattle manure application under 20 mm irrigation regime. He also observed that the quality of the amendment in Zai played a significant role. Low TDM as well as grain yield was produced with crop residue and compost of low quality. He observed for instance at the three study sites in Niger, that TDM produced on average with crop residue application was 756 at Sadore; 925 at Damari and 2185 kh ha-1 at Kakassi in 1999, compared to 3957, 4600 and 5030 kg ha-1 respectively with same rate of manure application. The grain yield was 151 kg ha-1 at Damari and 393 kg ha-1 at Kakassi with crop residue application, while it was 987 and 778 kg ha with manure application.

Ftondji (2002) observed that the Zai planting technique induced a higher water use efficiency than flat planting at three sites in Niger. Combination of Zai with manure improved considerably water use efficiency in three different sites. Therefore it is imperative to promote technologies that can on one hand help increase potential water availability and on the other hand consequently help rehabilitate degraded lands. "Zai" enhanced soil water storage and increased plant water availability, though most of this water could be drained out in soil with low water holding capacity as in Sadore and Damari in Niger. Nevertheless, the use of good quality organic amendment (manure) promoted rapid and deep root growth and helped limit water loss by drainage.

See also:

Southern adn East Africa Rainwater Network Searnet
IWMI Research in Africa Best Practices Zai Holes

ECHO Dryland techniques and Mulches

Drylands Coordination Group Integrated Plant Nutrition

Drylands Coordination Group Integrated Plant Nutrition Management in Mali pdf
Summary Report 1998-2004

Cornell University: Bio-Char Projects 2007

Bio-char Projects

Currently (January 2007) we conduct experiments to evaluate the effects of bio-char on nutrient adsorption, nutrient leaching, water percolation, soil water availability and carbon cycling as well as the stability and mobility of bio-char itself with research in our Ithaca lab, in Colombia, Brazil, Zambia and Kenya.

Adam + Partner Biocoal: Improved Charcoal Production System (ICPS) and Continuous carbonization system (CCS)
Chris Adam, Garmisch, Germany, February 2007

See the new biocoal web site where Chris Adams shows the charcoal production systems and stoves he has developed in Africa and Asia.

See other stories about Chris Adam

Green Charcoal by Pronatura International, France

Two billion people around the world use wood for household energy needs. This contributes significantly to the world's deforestation activities as well as increasing the risk of droughts and desertification. In an attempt to reduce deforestation, Pro-Natura has developed Green-Charcoal.

Charcoal Application and VAM Inoculation Promote Vine Growth, Yield and Qualtiy of Passion Fruits in Kenya
L. Wamocho, R. Michieka, K. Yamashita, T. Ishii
ISHS Acta Horticulturae 565: VI International Symposium on Temperate Fruit Growing in the Tropics and Subtropics

Abstract:

THE INTERPLAY BETWEEN SMALLHOLDER FARMERS AND FRAGILE TROPICAL AGROECOSYSTEMS IN THE KENYAN HIGHLANDS
A.N. Pell, D.M. Mbugua, L.V. Verchot, C.B. Barrett, L.E. Blume, J.G. Gamara, J.M. Kinyangi, C.J. Lehmann, A.O. Odenyo, S.O. Ngoze, B.N. Okumu, P.P. Marenya, S.J. Riha, and J. Wangil
POLICY BRIEF No. 3 January 2005

Long-Term Black Carbon (Bio-Char) Dynamics in Cultivated Soil
Binh Thanh Nguyen, Johannes Lehmann, and James Kinyangi. Cornell Univ, 1022 Bradfield Hall, Ithaca, NY 14853
18th World Congress of Soil Science (WCSS) July 9-15, 2006 - Philadelphia, Pennsylvania, USA