7.5+Managedsoil+erosion

=5. How can soil managed? (examples of ways to alleviate it) =

What are the issues?
As we have seen soil erosion often goes hand in hand with desertification, so by tackling one you can effect the other. Soil erosion can occur due to water in the form of sheets and gulleys and also the wind, and can be made worse by human activity. Desertification can occur where there is soil erosion and the rainfall is variable.If you can reduce the erosion, the soil structure and quality can be maintained and so desertification is less likely to occur.

So what are the ways of tackling these joint problems?
Soil erosion by water is more likely to happen if the rainfall is very heavy, particularly after a drought. But if the ground has structures in place to reduce run-off, the erosion will be far less damaging There are several main routes to achieve this : Have perennial plants – trees and shrubs – which will help hold the soil down, and act as a barricade to catch the soil that is being washed away. This can be in the form of bands of trees (these are more likely to survive than individual trees) or hedges of mixed trees and strubs Have a barrier to catch the water as it flows down the slope carrying the soil. If banks that are built across a slope of mud, this is known as terracing and is used in Ethiopia while in places like Niger and Burkina Faso, where they are built of rocks, they are known as bunds. Another method of trapping water is digging Zai pits, into which organic matter and seeds are planted. As the water runs down the slopes the water fall into the pits, where it soaks into the soil and also deposits any soil that it has eroded from up the slope. So small areas of good quality soil and organic matter and moisture is trapped. Keeping ground cover at all times to prevent the water washing the soil away, often known as zero or minimum till – in other words not ploughing a whole field after the crop has been harvested

Wind erosion occurs after a prolonged drought, when there is little remaining root structure to hold the soil in place and not much organic matter in the soil to act as a sponge to any residual moisture

The solutions are similar to prevent erosion by water:
Have perennial plants – trees and shrubs – which will help hold the soil down, and prevent the wind whipping it away. Improving the ability of the soil to retain moisture so it less easily blown away by measures including adding organic matter – this can either be achieved by adding organic matter to zai holes or by planting trees that shed leaves that add organic matter

So many of the solutions will be variations and combinations of
Planting trees and shrubs Adding barriers to reduce erosion Retaining the water in times of heavy rain Adding organic matter to the soil, so that it can retain water and provide plant nutrients Not leaving the soil as bare ground at any time There are specific ways in which these ideas are implemented that vary from place to place and are adapted to the particular circumstances. It is these examples we are looking for. While everyone produced some really good ideas, I think perhaps this is the best summary of the information on the Sahel we are likely to find: media type="custom" key="8265782" media type="custom" key="6143037"

media type="custom" key="6085773" media type="custom" key="6085781" =Other examples:=

Farmer Managed Natural Regeneration
Farmer Managed Natural Regeneration (FMNR) is a reforestation technique developed in West Africa in the 1980s and 1990s, now practiced on over 30,000 km² of land in the Niger Republic as well as Chad, Burkina Faso, Ethiopia and Mali. FMNR relies on the presence of remaining live tree roots, rather than planting trees fromelsewhere which will not be so suited to the ecosystem. FMNR in its simplest form is merely the selection and pruning of stems which sprout from indigenous tree and shrub stumps. Typically 10 – 20 stems may sprout from a stump. By selecting about 5 of the strongest stems per stump and pruning side branches, and by culling unwanted stems, very rapid re-growth can be achieved. Returning regularly to prune any unwanted new stems and side branches attains best results. One way to manage is that each year one stem from each stump is harvested so that with each passing year, subsequent stems are larger and hence more valuable. Farmers had traditionally cleared their land of all woody and herbacious vegetation in preparation for planting annual crops. Despite this, the remaining rootstock of the native trees continued to resprout each year. Farmers practicing FMNR trained these plants, and grew them into trees of between 3-6 meters in height. These farmers saw increases in crop yields, increased fodder production, fuel wood availability from prunings and thinnings, as well as the potential to sell firewood in drought years. Research into the application of FMNR by Dr. Chris Reij, (Vrije University, Amsterdam) has revealed that over 30,000 km² in danger of desertification have been revegetated through FMNR in Niger alone. Recent articles in the New York Times (February 11, 2007) and the UN wire service (March 7, 2007) have confirmed that Niger is the only country in Africa to see an increase of forest cover over the past 30 years. FMNR has played a significant role in this restoration of forest cover. Advantages: 2. Reclamation of degraded land. Leaves, twigs and small branches placed on hardpan areas are rapidly incorporated into the soil profile by termites. This improves the soil structure and breaks the hardpan, thus allowing good infiltration and reduced soil erosion. Within only one season totally unproductive hardpans can be restored to fertile fields. 3. Crop yields and animal productivity are improved. Grazing animals are attracted to edible tree pods so spend more time on the farms and depositing manure. Trees provide shelter and shade for crops, reduce evaporation, soil temperatures, and soil erosion, and provide valuable mulch which improves soil fertility. With FMNR farmers have enough wood for cooking and building requirement so crop residues are left on the fields for mulching. 4. Increases in biodiversity have a positive effect on the entire region. Animals and birds have re-entered the region along with many predatory insects that reduce the need for pesticides and hence restore a balance in the ecosystem.
 * 1.** Firewood and building timber is readily available for personal use and for sale. Even quite small producers can make 2 months food money for a family from selling their extra wood, while others can make considerably more.

Further Links to ideas:
http://lindym.wordpress.com/2010/05/20/australian-acacias-for-africa/ Details of just how acacia works and how widespread its uses are @http://lindym.wordpress.com/2010/05/20/making-the-most-of-what-you-have/ As it says, while this not strictly an example of managing soil erosion directly, by growing over 12 months in a sustainable way, the ground cover is maintained and so wind erosion is less likely

= MUST SEE VIDEO - push the slider to 11 minutes for Burkina Faso = media type="custom" key="7472981" A great site to trawl through: @http://www.agfax.net/theme.php?t=5