Introduction:
- Desert margins are most vulnerable to desertification E.g Sahel Region of Sub Saharan Africa
Causes:
- 80% of Burkino Faso live on water fed agriculture leading to over cultivation
- Irregular rainfall: 200-600mmpa with several droughts
- Fragile aridsols- low in nutrients and prone to lateralisation – chemical weathering which produces a wide variety in the thickness of soil
- In Dry seasons deflation takes fertile top soil
- Population increase = pressure
- Pastoralism is the branch of agriculture concerned with the raising of livestock- compaction
Social Impacts:
- 1975-1985: Population of the village Ranawa dropped by 25% due to infertile land
- Land abandonment leads to desertification = Positive Feedback Loop
- Many moved to Ivory Coast for work or made the dangerous journey to the UK
- BUT since 1985 no families have left due to zai
- Annually 20 million tonnes of cereal lost due to desertification
Mitigation and Adaptation:
- Yacouba has been successfully using a traditional farming technique called Zaï to restore soils damaged by desertification
- The process:
- Agroforestry: is a land use management system in which trees or shrubs are grown around or among crops or pastureland
- Used Contour buds and stone walls to slow rate of water flow
- Dig deep holes in summer months to prevent duricrust formation and hold any surface runoff in wet seasons- also helps raise water table
- Termites in holes break down organic matter and turn over and aerate soil
- Agroforestry: is a land use management system in which trees or shrubs are grown around or among crops or pastureland
Alternatives Futures:
| Positive | Negative |
| · Success of Zai
o Since 1985 no families have left due to zai o 30 acres of degraded land now have forest growing on it in 20 years · SPAIN: Andalusia and Almeria – driest region in Europe BUT Spain is Europe’s biggest producer of strawberries, 95% come from Andalusia due to drip irrigation |
· 2.5 million facing starvation in Burkino Faso after drought = soil desertified and dry with duricrust = Impossible to grow crops
· SPAIN: Drip irrigation: : investment has reduced water waste and promotes efficient water resource use and limits demands BUT 40% illegally irrigated using water from black market |
2 EXAMPLE ESSAY PLAN: To what extent is soil fertility the most significant factor in food security
INTRO: Food security definition BUT soil varies depending on climate BUT we can adapt and mitigate
P1: MOST IMPORTANT: 2.5 million facing starvation in Burkino Faso after drought = soil desertified and dry with duricrust = Impossible to grow crops
P2: BUT adapted: Zai-digging holes with termites and nutrients in dry seasons and allowing to flood = SUCCESS: 20 hectares of land made productive in 10 years
P3: Supply of artificial fertilisers most important: USA only 1-2% of phosphors and potassium reserves left due to exploitation – BUT would not need fertiliser is soil fertile
CONCLUDE: Pop + = Urbanisation = Land degradation = – Food production as in South Sudan
BUT Boserup = Innovation as seen in Green Revolution and GM crops