Introduction to managing desertification and soil erosion

1. Introduction to managingdesertification and soil erosion

2. 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.

3. 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 2 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. • Have a barrier to catch the water as it flows down the slope carrying the soil. • Keeping ground cover at all times to prevent the water washing the soil away

4. So what are the ways of tackling these joint problems? • 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

5. 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.

6. The Sahel Region By Akram Akram has explained the problems well and suggested the direction for solutions without giving any concrete examples

7. What is the Sahel? • The Sahel is the region between the Sahara and the Savannas in Sudan and Chad. • It runs 2,400 miles from the Atlantic Ocean and creates a belt all the way to Red Sea. • Mostly covered in grassland and savanna.

8. The threat of desertification • A United Nations Environmental Programme shows that 6.1 billion hectares of land on Earth is dry desert. • Areas that are Sahel regions are vulnerable to becoming desert. • A UNEP publication confirms that the natural green belt extends across the Sahel. It exists because it is closer to the desert than the agricultural zone and therefore too dry for sustainable millet production. Careless use, however, could easily destroy this zone.

9. Maradi Niger by Emilie • This is one example I had come across and I think it is a really neat one – and very effective as you will see

10. Maradi Niger

11. What is FMNR?? • FMNR is a self – promoting reforestation system. This system started when the farmers cut down the tropical rainforest and made it into fields which led to soil erosion. Now though instead of chopping the stems, that grow from the underground tree stumps, they let them grow and use them for firewood and timber.

12. Benefits The firewood and building timber the farmers get is good quality and is good for sale or personal use. Fertile fields can be regained because this system helps to improve the soil. Increases biodiversity so that animals who lost their homes when the rainforest was destroyed can start to move back. Income generation – farmers are able to sell the firewood to make money to support their families. Problems Some of the fields may not produce shoots from the stumps. In very dry areas the shoots do not grow very quickly. The benefits and problems of this system.

13. FMNR in action. • FMNR has transformed the landscape to provide a workable method of reversing the devastation caused by desertification

14. Now here are several examples from other classes that came in too late for their lessons so I thought I would add them to the library of ideas and share them with you too

15. Made by Chan Zimmermann Homework: Geography

16. Why is there desertification and soil erosion in the region of Sahel? The Sahel region is a semi-arid region that it turning into a desert. The desertification is caused by the human being and the environment Desertification caused by humans: They have left the animals graze the land and that destroyed the vegetation. They have cut down trees and bushes for fuel, making the land lose water. Lack of technology for agriculture. No environmental policy, urban and industry activities. Desertification caused by nature: climatic changes like temperature, lack of rain, etc...

17. Solution for the desertification and erosion in the Sahel (1) • One solution that there are doing is the migration to another place. The migration is a good idea because it will stop desertification in a way or slow it down by less over grazing, deforestation, a good idea because and over cultivation. But lots of people, like farmers and people with a job, don't leave because they would loss there job. • The UN and aid organisations have helped the local people by giving them money and shelters and schemes them get along.

18. Solution for the desertification and erosion in the Sahel (2) • In the windy areas, the faces of sand dunes can be covered by large boulders or oil to keep the sand from moving. • Sand fences can be built in the same manner that snow fences are used in the northern United States. • Plants can also be irrigated and grown at the base of sand dunes. Since the plants bind the soil, this helps prevent erosion and stop the blowing sand.

19. Photos of the Sahel region

20. India • Desertification is a major problem in the drylands of India, affecting the way of life for its inhabitants. The problem is more severe in the arid lands in the north-western part of the country. The ones more affected by the desertification are Haryana, • Lot of organizations have carried out researches for better technologies to counter the ill-effects of desertification in india

21. Solution for the desertification and erosion in India • Wind Erosion Control: A number of mechanical and chemical methods are available globally for the control of wind erosion, but looking to the fact that this desert is highly populated and has a dominantly agricultural economy, rather than nomadic and pastoral one, many of the mechanical and chemical methods of control can not be implemented. • So far, the large-scale wind erosion control measures in India have been sponsored by the Government. Farmers protect and manage their fields especially through crop residue management and fencing during critical periods. Two major activities of wind erosion control are sand dune stabilization and shelter belt plantation.

22. Solution for the desertification and erosion in India • Soil and Water Conservation: To counter crusting of soil and its subsequent erosion from the agricultural fields a number of practices have been suggested. In the black soil areas ridge and furrow system may help to reduce the problem of water logging, while in the hard pan soils deep ploughing at 3-4 years’ interval will ensure better infiltration and root growth. Mixing crop residues and organic matter with light textured soils help to increase the soil moisture and crop yield.

23. This is part of one from Ross He did some good stuff on FMNR which I will leave in the PP on the wiki

24. How desertification is being managed in Spain Spain was the first industrialized country to act on the recommendations of 1977 Nairobi Conference on Desertification. Spain has been restoring degraded land for well over 100 years and since then it is estimated that 5 million hectares of land has been reforested, to prevent soil erosion. Many different measures have been implemented like, making sure no water is wasted and water usage is not excessive. Also obliging farmers to follow a code of good practices. In addition, forest fires are commonplace, so a 10 million euro fund has been set up so these can urgently be replaced.

25. In the centre of Spain, there is very often droughts and water shortages. This means that the management of water is a very big issue. One that is being tackled by many different organizations and groups. For people living in the centre of Spain, desertification must be reversed if they are to keep their livelihoods.

26. This is from Alec A series of really useful thoughts

27. The American problem In America there used to be massive herds of bison which would stay clustered in tight herds for safety from predators. Their hooves and urine killed the moss while desirable plant seeds were pounded into the soil to germinate and also pounded organic materials into the soil which aided plant growth. The bison would then move on allow the plants to grow, preventing desertification. However because now there are cattle ranches with cattle roaming unopposed by predators and free to roam and do not trample and destroy the weeds and other inedible plants that like the bison did and this blocks sunlight and reduce plant growth. They also do not tread organic matter into the soil as they are sparsely spread out and this means there is less water retention in plants and less plant growth. This is creating an American Sahara However Don and Cleo Shaules, near Billings, Montana, have embraced a new idea of using cattle to do the job the bison's once did.

28. The American solution By mimicking the historical sequence of grazing with the aid of carefully laid out fences, to put more animals in smaller spaces for shorter periods of time. They also herd the animals, or put feed or supplements in areas where the impact is especially desired. The impact of the animals effectively breaks down old plants while also effectively ‘immunises’ the landscape with bacteria in the form of manure. With heavy animal impact the Shaules have successfully trampled cactus and sagebrush into the dirt, while "rototilling" the soil to favor new seedlings. The rich, brown soil humus increased from 1/4 inch up to 1 1/2 inches in just ten years, and the Shaules have been able to more than double their livestock numbers. “We wintered our "herd" of one cow on the most brittle, erosion-prone part of our land. Hay was put out in a different spot each day, and any that was not eaten was trampled into the ground, resulting in an explosion of new seedlings and growth in spring.”

29. Afforestation in the Sahel Farmers in the Sahel are reclaiming the desert by turning its barren wastelands into green, productive farmland, that could potentially be used as a base for bio-energy feedstock production. Satellite images taken this year and 20 years ago show that the desert is in retreat thanks to a resurgence of trees. Which are mainly ana trees (Faidherbiaalbida), a type of acacia, which is itself a kind of energy crop. Wherever the trees grow, farming can resume. Tree planting has led to the re-greening of as much as 3 million hectares of land in Niger, enabling some 250,000 hectares to be farmed again. The land became barren in the 1970s and early 1980s through poor management and indiscriminate felling of trees for firewood, but since the mid-1980s farmers in parts of Niger have been protecting them instead of chopping them down. By also combining the project with simple measures such as ditches and holes to catch scarce rainwater and save it for irrigation, the programmes are helping communities in Niger re-establish control over desertification, simultaneously halting the march of the desert and helping to prevent famines like the one that hit Niger in July 2005. “Where 20 years ago there was barely a tree, there are now 50 to 100 per hectare. Production of cereals has soared”

30. Managing irrigation and natural waterways in North Coast Orchards This project was part of a wider project to combat soil erosion in the North Coast of Australia which is badly affecting landowners there. The site helped in the project was an old macadamia orchard which had been established with little regard for natural watercourses. As a result there was extensive sheet erosion with exposed tree roots, and gullies had formed where water flows concentrated in the orchard. The damage to the orchard floor meant machine-harvesting in those areas of the orchard was ineffective. The new landowner of the site wanted to reduce the dramatic soil loss and improve machine-harvesting while maintaining existing production levels.

31. The Solution Firstly gullies running down between the lines of trees were filled with large gravel. Some trees in the way of natural flow lines for water, and also trees which over-shaded areas stopping sunlight getting through to the grass, were removed and others pruned to help grass to grow over the top of the gravel, which would allow machine-harvesting. The filled gully functioned as both a subsurface and surface drain which allowed water to flow across the tree rows and small rock check dams were installed to slow the water down and encourage sediment deposition rather than the water just washing the organic matter out of the orchard. After the scheme the land’s active gully erosion and sheet erosion through the orchard had been greatly reduced by slowing the water flow and allowing sediments to improve the soil structure and resist soil erosion. The extra light from removing specific trees also improved groundcover and because sediments were being trapped within the orchard, rather than ending up in dams and watercourses, the soil composition and structure benefited and plants were able to obtain the water and nutrients they needed. Another positive of the scheme was that the orchard’s production was not been interrupted or set back by the erosion control works so the landowner really ended up with a win/win situation.