4.01.2016

COMBATING DESERTIFICATION

Global Bilgiler  /  at  13:54  /  No comments


What can we do?
Combating desertification and promoting sustainable development areclosely linked due to the social and economic importance of natural resources and agriculture. As we know, when people live in poverty, they have little choice but to over-exploit the land. This is the circle that the UNCCD, through its work, seeks to break.
As with many other environmental challenges, it is less costly to stop the damage happening than to solve the problems it causes. Once desertification is a reality, repairing its impact is a long and costly process. Despite the severity of land degradation, it is not necessarily final. By employing good agricultural practice, the trend can be reversed, for example. To preserve soil productivity, sustainable long-term practices must be applied.
UNCCD Best Practice approaches focus on:
• Sustainable Land Management (SLM) technologies, including adaptation;
• capacity-building and awareness-raising at various levels;
• desertification, land degradation and drought, and SLM monitoring and assessment/research;
• knowledge management and decision support;
• the policy, legislative and institutional framework;
• funding and resource mobilization; and
• participation, collaboration and networking.
INCREASE Population resilience
One valuable way of slowing the process of desertification is to reduce people’s vulnerability by increasing the availability of alternative livelihoods and strengthening their resilience. This can be done in a variety of ways.
Preventing land degradation is obviously essential where it is possible, and where it is not recovery and rehabilitation are good options. Mainstreaming sustainable land management, drought-risk management and biodiversity considerations into the design, implementation and monitoring of adaptation action at local national and regional levels is clearly central to any attempt to slow the progress of desertification. Climate change adaptation will need to find a concerted way to address poverty reduction and vulnerability to changing conditions.
Insurance schemes for small-holder agriculture can give farmers greater security, and Ethiopia and Kenya are piloting schemes which offer them insurance against crop failure. The ultimate goal is to provide a large-scale insurance scheme for the population. However, at the moment only very few benefit from such a scheme. Beyond that, land reform (in which Kenya again is making progress) can play a major part in improving people’s ability to cope, including by making sure that they enjoy security of land tenure. Aleasehold forestry project in Nepal is also achieving valuable results.
Supporting science-driven agriculture is clearly essential, as it is the way to enable farmers to take advantage of up-to-date developments and best practice which has worked elsewhere. Rainwater harvesting, droughtresistant crop varieties, agro-forestry and efficient energy use will all contribute to sustainable land management and improved ways of managing drought risk. Although it may sound too obvious to need mentioning, sharing research and information on the factors which contribute to desertification and on ways of combating it - the policies and practices which make the real difference - must not be neglected.
Improving resilience also means, of course, learning to be aware of and responsive to the needs of the natural world, adopting a holistic biodiversity and ecosystem approach, conducting and acting on environmental impact assessments, and observing the principles of sustainable use.
Further, it is well established that the dry areas and threatened areas are overpopulated, therefore unable to support human and livestock populations. One of the main keys is to reduce the dependence on these lands via creating jobs in other sectors note based on cultivation, or on range or forest lands.
Beyond these approaches, there is much more that can be done, for example partnership building for sustainable investments. This will involve:
• institutional strengthening at local level;
• governance empowerment and capacity development; and
• targeting women and youth.
IMPROVE Land management
To combat desertification it is necessary to restore and fertilize the land.
Nutrients such as nitrogen, phosphorus, calcium, magnesium etc. must be in the soil for plants to grow. When the soil has lost all or part of its nutrients and may also have accumulated toxic elements such as salt, it is degraded and its productivity diminishes as a consequence.
Intensive agriculture is one of the main reasons for the soil to degrade, and once that has happened it is necessary to re-establish soil fertility by using either synthetic fertilizers or natural compost. The soil regenerated with organic matter in this way will produce more fruitful harvests. The restructuring of the soil is potentially a very effective and sustainable way to maintain soil fertility.
There is also a cultural aspect linked to land management and the challenge of overgrazing. It can be hard to convince local farmers to adopt the ideas of giving land time to recover and reducing herd numbers. In many countries the amount of livestock is a source of pride and honour for the owner, their family or clan. A possible solution can be to improve cropping techniques in cultivated areas, release land for cattle and hence reduce pastoral pressure and the degradation that results from it.
Diversify production
Diversifying crop and animal production allows better use of land resources and prevents over-production of a single species or crop. A plot can sustain different plants and animals over long periods, since their nutritional needs vary and the resources they remove from the land are complementary. Mixed farming reduces the loss of agricultural products in the case of a natural disaster, and certain production methods are obviously better adapted to counter drought than others.
Each plant species has specific nutritional needs, for example maize rapidly exhausts the soil much faster than other plants. In many cases prolonged monoculture should be avoided on the same plot of land and a system of rotational crop production should be established to restore soil fertility.
RESTORE LAND
Land degradation need not be permanent. To restore degraded lands, crop techniques should be improved by stabilizing the soil while enriching it with organic matter, and selecting different crop varieties. Even the slightest water levels can be used to irrigate and make unproductive soil productive. It is also important to combat marked soil salinity by employing the most effective system of irrigation. This involves removing any surplus water, monitoring the changes in groundwater reserves and soil salinity in the problem areas, draining, irrigating and planting trees whose roots will prevent the soil leaching away. Trees in turn act as a windbreak and provide supplementary resources like wood, leaves and fruit.
Experience shows that reforestation is a very effective approach to restoring land. It requires the creation of nurseries to nurture young plants from local species selected for their rapid growth and adaptation to the harsh climate. In rangelands, rehabilitation through shrub planting or seeding of appropriate species is also an effective means of land restoration. Reforestation is a longterm action since tree growth is slow. Fortunately, the trees’ long life cycle means that the investment is generally viable.
Trees play several roles:
• they fix soil particles and prevent erosion by water and wind;
• act as obstacles to the wind and so protect crops;
• enhance soil fertility since many trees produce nitrogen that fertilizes and increases soil productivity;
• facilitate water penetration in the soil during rain and contribute to maintaining humidity for long periods;
• provide shade for animals and people;
• supply nutrients because fruit trees diversify food sources and provide fodder for livestock; and
• provide a source of firewood and construction materials.
 Erosion
To prevent desertification or to restore the productivity of damaged soil, erosion control is essential. A number of simple mechanical means alleviate the effects of wind and prevent the displacement of sand and dust. These include:
• the construction of fences or barriers from local plant species, woven palms, planted hedges or metal sheeting around villages and crops;
• planting vegetation whose roots protect and fix the soil;
• prohibiting livestock from grazing to protect the plantation areas.
USE Non-wood energy sources
All human societies use energy, which is vital for their proper functioning and development. Today, a large number of populations use wood as their major source of energy, which contributes to worsening desertification through deforestation and also increases the greenhouse effect by releasing carbon dioxide.
The non-sustainable use of forest resources as a source of energy is a factor in desertification. Identifying and employing alternative renewable energy sources are therefore important in the fight against desertification.
Solar energy
Given the right technology, the bright, sunny conditions characteristic of arid and semi-arid regions, can satisfy energy needs in these areas. However, this may be still too expensive for widespread use. Ideally solar energy would be the obvious choice, and could be used in many ways, for instance:
• greenhouses integrated into the dwelling structure with panels that store energy from the sun in batteries (to supply hot water);
• parabolic mirrors to help cook food and produce steam for running steam turbines;
• photo-voltaic panels to transform the sun’s rays into electricity. The electric current is stored in batteries and can be used day or night; and
• the evaporation power of the sun can produce distilled, salt-free water by means of a solar distiller.
 Wind
Wind turbines need to be set on open exposed areas with high average wind speeds (at least 20 km/h). However, wind energy is growing rapidly because it can provide more energy on a large scale than solar power. In drylands with frequent winds, this form of energy could be an important complement in the long term. For example, wind energy can facilitate irrigation and water supplies for livestock.
One of the greatest advantages of wind energy is that it is plentiful. It is also widely distributed, cheap, does not emit toxic gases, and avoids uncontrolled tree-felling or fuelwood collection.
Biogas
Natural gas and biogas are in essence the same fuel but from different origins. While natural gas is a fossil fuel, biogas is a renewable fuel produced through the fermentation of organic materials such as household or agricultural waste. The high temperatures in the drylands are beneficial to biogas creation. Biogas has several advantages. For one thing it is cheap to produce and can be used for lighting, cooking or to drive motors. It can also be produced in small installations, especially in regions where agriculture and cattle rearing coexist.
In developing countries, over 500 million households still use traditional biomass for cooking and heating. Elsewhere 25 million households already cook and light their homes with biogas and a growing number of small industries, including agricultural processing, obtain process heat and motive power from small-scale biogas digesters. Biogas is an example of a stationary use application thought to have particularly good potential as a renewable  energy source with good greenhouse gas savings, especially when waste is used. Nevertheless, when energy crops are used for biogas, ecological and land use concerns need to be considered.
Find alternative solutions
Biochar
Land has an unparalleled capacity to hold carbon and to act as a sink for greenhouse gases. It is therefore imperative to focus on activities that enhance the rehabilitation, protection and sustainable management of degraded lands. Conventional means to increase soil carbon stocks depend on climate, soil type and site-specific management.
Biochar is charcoal created by a process called biomass pyrolysis (the decomposition or transformation of a compound by heat), and differs from charcoal only in that its primary use is not for fuel but for but for improving agricultural soils. Biochar was added to soils in the Amazon basin several hundred years ago with the affect of improving agricultural production..
Biochar is of increasing interest because of concerns about climate change caused by carbon dioxide and other greenhouse gas emissions. The pyrolysis or carbonization process is well known and can be implemented on a small scale (e.g. a cooking stove) as well as on a large scale (e.g. a biorefinery). About 50 per cent of the carbon can be captured when biomass is converted to biochar.
Some types of biochar can improve soil texture, thereby increasing its ability to bind and retain fertilizers and release them gradually. It naturally contains many micronutrients needed by plants and is safer than other “natural” fertilizers such as manure or sewage, having undergone high-temperature disinfection. Because it releases nutrients slowly, it poses much less risk of water table contamination. Recent studies appear to show that soil biochar is capable of increasing soil fertility by improving its chemical, biological, and physical properties. It significantly increases plant growth and nutrition, and improves the efficiency of nitrogen fertilizers in fields containing biochar.
The fact that many of the dryland soils have been degraded means that they are currently far from saturated with carbon and their potential to sequester carbon may be very high.
The avoided emissions of greenhouse gases are between 2 and 5 times greater when biochar is applied to agricultural land than used solely for fossil energy offsets. As such, this approach of soil organic carbon restoration could contribute a significant adaptation tool to climate change, in addition to sequestering carbon. Having said that, research on biochar is still underway and many critically important issues have yet to be understood. Thus far there has been little public awareness or debate about the wide-scale application of biochar. Further, the pyrolysis conditions and the biomass feedstock will affect the suitability of biochar for improving the productivity of agricultural soils, with some types of biochar having the potential to seriously reduce soil fertility and agricultural productivity. It is therefore vitally important that only suitable biochars are added to agricultural soils. It is imperative that errors as they have been made in other areas are avoided, such as further land conversion.
Zero-tillage farming
Zero-tillage farming (also called no-till or no-tillage) is a method of plowing or tilling a field in which the soil is disturbed as little as possible by, essentially, not plowing the field. The crop is planted directly into a seedbed which has not been tilled since the harvest of the previous crop. This way farmers can increase the amount of water in the soil and decrease erosion. It may also increase the amount and variety of life in and on the soil, but may require increased herbicide usage. Zero-tillage also improves the structure of the soil by maintaining soil cover. It implies leaving the residues of the previous season’s crops on the farmland, which can increase water infiltration while  reducing evaporation as well as wind and water erosion. The additional use of other soil fertilization techniques is also promising, at the same time increasing moisture capture, which is associated with carbon sequestration.
Less soil tillage reduces labour, fuel, irrigation and machinery costs. Zerotillage can increase yield because of higher water infiltration and storage capacity, and less erosion. Another benefit of zero-tillage is that because of the higher water content, it can make economic sense to plant another crop instead of leaving a field fallow.
• Conservation of soil moisture;
• Reduction of soil erosion by the wind since the crop residue cover isn’t plowed under the soil;
• Reduction of farm labour (i.e. time actually spent tilling the field, fuel consumption) thereby reducing farm expenses;
• Increased planting and harvesting timelines, since time spent tilling and preparing the field required;
• Earthworms, and other biological organisms, are left alone to live and manipulate the soil by creating tunnels, which otherwise would be created by tilling. This allows for good movement of water and air throughout the soil for good plant growth;
• Reduced soil compaction. Many years of tilling lead to a very hard, densely packed soil; and
• Increased soil organic means better soil structure and more available nutrients for plant growth. Tilling ‘burns’ organic matter away.Increasing soil organic helps to sequin the soil.

While these aspects make zero-tillage a promising tool to reverse soil degradation, one should remain alert to potential negative impacts it might entail, such as increased pesticide use. It is recommended to consider advanced research and local conditions before adopting new techniques to achieve the greatest benefits.

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