Land sources are finite, fragile and non-renewable. They include soil, which is mainly important for agriculture; land cover, which is important for the environment; and landscapes which are an important component of human habitat and welfare(GEO 3, Pg-62). Land degradation caused by human activities, has been a major global issue during the 20th century will remain high on the international agenda in the 21st century. Land degradation leads to a significant reduction of the productive capacity of land. Human activities contributing to land degradation include unsuitable agricultural land use, poor soil and water management practices, deforestation, removal of natural vegetation, frequent use of heavy machinery overgrazing, improper crop rotation and poor irrigation practices. It has been estimated that 23 per cent of all usable land(excluding mountains and deserts, for example) to reduce it productivity( UNEP 1992, Oldeman, Hakkeling and Sombroek 1990).
In the early 1990s about 910 million ha of land were classified as ‘moderately degraded’, with greatly reduced agricultural productivity. A total of 305 million ha of soils ranged between ‘ strongly degraded’(296 million ha) and ‘extremely degraded’(9 million ha, of which more than 5 million ha were in Africa). ‘Extremely degraded’ soils are beyond restoration(Oldeman, Hakkeling and Sombroek 1990).
Despite these compelling statistics on land degradation, some studies are beginning to question the data, arguing that degradation estimates are overstated. A major reason suggested for the over estimation of land degradation has been underestimation of the abilities of local farmers that ‘……experts need to discriminate more carefully between a naturally bad state, a temporary bad state and a degraded state of land’.
Distinguished Participants, what are your opinion about this debate and haw do you think, is land degradation inevitable? Why?
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Well, Thuza, you gave a very macro picture of land degradation. It's very difficult to answer your question. It can and should be "clustered out" into a smaller sectors and issues, such as, highland area, lowland basin, dry lands, and coastal, the list can go on. Each type has a certain agicultural practice and system. Be a bit more focused.
According to the Food and agricultural Organization report 2004, A degraded land is a any land which due to natural processes or human activities is no longer able to sustain properly. From this definition, we realize that land degradation does not only consist of the whole environment, but includes individual factors such as soil, water resources, grasslands, crops, and biodiversity[Hubert George,2004].
According to the land degradation assessment in dry lands LADA, 2004 report,, Humans are the central cause of degradation due to activities like deforestation, overgrazing, agricultural activities,, over exploitation, of vegetation, and industrial activities. Land degradation just like desertification, is among the central; issues facing the international community as it aims to meet the Millennium Development Goals by 2015[UN report, October 2005]. This is solely because degradation in arid, semi arid and dry humid areas is a world wide problem leading to poverty and forces migration.
I think the underestimation of the abilities of the farmers by experts is not appropriate in estimating land degradation. This is because experts fail to understand that farmers have a wide range of choices to draw from. For example, studies carried out by Mazzuucato and Niemeijer,[2001], shows that farmers have developed flexible, efficient and effective land management to deal with the limited availability of labor and external inputs. They have been able to adapt to social institutions to accumulate opportunities for increased market as well as constrains posed by increased natural resource scarcity. Over estimation also a results from naturally poor state of soil and drought related declines.
Therefore in order for experts to rightly assess degradation, they need to deal with both spatial and temporal dimensions of problems they observe.[Fresco and Kroonenberg, 1992]. This is when they need to discriminate between the different states of land degradation.
Therefore I stand tall with the opinion that degradation is not inevitable. It is clear that farmers have not achieved environmental sustainability through capital intensive paths [Rardon et al 1996], but farmers can adjust to this land management practices in an environmentally sustainable way which include; soil and water conservation practices which does not only refer to mechanical practices, but also to less conspicuous agronomic and biological practices such as mulching, selective clearing and adapted plant species.[Mazzucato et al 2000].
Land degradation also a major global environment and sustainable development issue. It is broadly defined as "any form of deterioration of the natural potential of land that affects ecosystem integrity either in terms of reducing its sustainable ecological productivity or in terms of its native biological richness and maintenance of resilience.(GEF 1999)
Land resourses can suffer degradation from human activities, in turn affecting water and biological resourses,often land degradation weakens the ability of communities to depend on the enviornment for their livelyhoods.This is seen ciearly when land resourse potential is diminished through desertification and deforestation.Activities that contribute to land gradation include,soil erosion,denudation
,pollution, loss of organic matter,fertility and vegetation cover,invasive species,habitat conversion(whether urban or agriculture)and aquifer degradation
The negative impacts of land degradation are both ecological and socioeconomic.
Land degradation undermines the structure and functions of ecological systems such as the biogeochemical science(i.e.Carbon, hydrological and nutrient cycle that are critical for the survival of human being .This impact has already put at risk the livelyhoods and economic well being, and the nutrient status of more than billion people in developing countries.(UNDP/GEF)
Causes identified for the Land degredation are water and wind erosion process, waterlogging and salinization, soil compression, inappripriate land use, mainly unsustainable agriculture practices, overgrazing and deforestation.
So, its a worldwide phenomenon substantially affecting productivity in over 80 countries on all continents except Antartica.Land degradation is especially serious in Africa where 36 countries face dryland degradation or desertification.
Agricultural lands both dryland and forest area have been most sevearly affected by land degradation. They cover about one fourth of the worlds total land area and account for 95% of all animal and plant protien and 99% of all calories,consumed by people,About two third of agricultural land have been degraded to some extent during the last 50 years.(GEF 1999).
HOwever, according to the past experirnces, Succesful land degradation prevention and control programs require scientifically sound and cross sectoral approaches to land management that integrate the ecological,economic, and social dimensions of land degradation issues in program design.These programs are most succesful when effective participation of stakeholders,
including women,at all stages. Early intervention in areas vulnerable to land degredation such as ecologically sensitive marginal lands is essential in preventing and controlling land degradation.
An appropriate enabling environment including policies, regulatios and economic incentives to support sustainable land management is necesary for effective local national and international response..
Capasity building at the community and national levels is necesary for the succesful implementation of on the ground activities.
The most effectively facilitate innovation,demonstration,and replication of good sustainable land management practices,
including indegenous management systems should be adopted in the ground activities.
Land resources can suffer degradation from human activities, in turn affecting water and biological resources. Often, land degradation weakens the ability of communities to depend on their environment for their livelihoods. When land resource potential is diminished through desertification and deforestation. Activities cause land degradation, soil erosion, denudation, pollution, loss of organic matter, fertility and vegetation cover, invasion species, habitat conversion (whether urban or agricultural) and aquifer degradation.[UNDP]
In my opinion, land degradation is an unavoidable situation especially impact on the poorest countries because firstly, this event comes from human activities that are caused soil erosion due to over- cultivation, deforestation, overgrazing, habitat conversion and aquifer degradation leading to a loss of vegetation and soil cover. Secondly, land degradation is a result of nature such as water and biological resources. Moreover, the mechanisms that initiate land degradation include physical, chemical, and biological processes. Physical process – decline in soil erosion structure leading to crusting, compaction, erosion, desertification, anaerobism, environmental pollution, and unsustainable use of natural resources. Chemical process – acidification, leaching, decrease in cation retention capacity, and fertility depletion. Biological process – reduction in total and biomass carbon, and decline in land biodiversity. Soil structure is an important property that affects all three degradative processes [Environmental Studies, Benny Josph, (2006)]
Additionally, land degradation also effect on the food security and the quality of life so the land quality and the productivities reduce. This is an another factor which causes poverty.
I would like to discuss about soil erosion with Thuzar.
Between human activities and natural processes, which one has the most impact on soil erosion? From my point of view, both cause soil erosion, but human activities have accelerated the rate of it, whether intentional or not.
Deforestation, urbanization, infrastructure cause soil erosion: human or natural?
Wind, water, river channel changes, salinity also cause soil erosion: human or nature?
In some countries, especially, in the drier countries, wind erosion may become a major cause. For example, in the Great Plains region of North America, there have been four serious periods of wind erosion, Eldon D. Enger and Bradley F. Smith, 2008.
I think the clearest example of human activities that have accelerated the rate of soil erosion is dam building. The effects of dam construction are to encourage sedimentation in the upstream reach and erosion in the downstream reach, V.M. Castillo et al, 2006
But, I still have doubt about land degradation figures, whether the estimates are correct or not. One estimated figure I would like to share with you: “The US Pimentel found in 1974 that the US lost 30 tons of top-soil per hectare, whereas we now know that the true figure was 12 tons per hectare”, Lomborg, 2001:105, the Skeptical environmentalist: Measuring the real State of the World.
I agree that land (soil) degradation is a serious problem because land is the major resource for food production. To solve environmental problems requires tremendous corporation, it depends on many factors, e.g. the willingness of people. I believe that a lot of people, especially the 9 people in our programme, have willingness.
Land is a critical productive asset on which many livelihoods depend, particularly in the developing world. For the poorest drylands populations, land degradation is a major factor that affects the ability to achieve food security and enhance livelihoods. Because drylands typically have low vegetation cover, they are particularly vulnerable to mismanagement which removes grasses, bushes and trees that protect the thin layer of fertile topsoil from the ravages of wind and waterborne erosion. Through poorly-managed intensification of land use, and deforestation, productive drylands can be degraded into unproductive land that cannot support agriculture, or sometimes not even pastoralism.
In my opinion, land degradation continues to be considered as a major problem worldwide and a serious challenge to food production and security in developing
countries. The blame for land degradation is put on farmers who are "not educated enough or not willing to take conservation measures or whatever." In fact this is
not fair. land degradation/conservation problems in developing countries requires the availability of appropriate technologies, but this alone will not be enough. The proper way of thinking, taking into consideration all relevant socioeconomic and cultural aspects, is an integral part of the right approach to dealing with such problems. In many developing countries there is a growing awareness of the need to expand cultivated areas to meet the basic needs of the fast growing population. However, the dangers that threaten the existing, oftenly limited, land resources have rarely been considered seriously by the planners and policy makers.
The two key issues concerning land degradation are as follows: firstly whether we can increase the productivity of the land through the use of technology, secondly whether world populations will continue to grow and increase land degradation. The technological argument is based on the fact that we can make crop land more productive through the use of fertilizers, pesticides and genetically modified seeds (GMO). The second point is linked to the first point and concerns our ability to provide for the food, consumer goods and energy demands of a growing population. Both scenarios will have a detrimental impact on the land and our quality of life.
The green revolution proved that our ability to manipulate natural forces to increase the productivity of crop land is limited. Vandana Shiva states “..the assumption of nature as a source of scarcity, and technology as a source of abundance, leads to the creation of technologies which create new scarcities in nature through ecological destruction.” That is to say technology increases productivity and simultaneously decreases the quality of the soil. The problem is impacted by the toxic effects of pesticides and fertilizers on the farmers and the food produced under this process. Moreover, eutrophication of water sources from these pollutants has adverse effects on inland and coastal waters (Millenium Ecosystem Assessment). According to the natural cycling of nutrients, both terrestrial and marine ecosystems are affected by human impacts on the land.
The growth of global populations has doubled in the past 40 years and increased by two billion people in the last 25 years (MA). Although, the populations of some developed countries have stabilized, those of developing countries continue to grow. More importantly, people are migrating to the cities for work, which places increasing demands on the surrounding communities to provide crucial support services: such as water, food and energy. As income levels rise in countries like India and China, there is an increasing demand for consumer products and energy and further land degradation. If these countries increase their consumption level to that of the US, there will not be sufficient natural resources to serve worldwide demand. This scenario may lead to war, conflicts and chaos throughout the world.
In conclusion, land use and population growth are intimately connected through global biogeochemical cycles. Technological development of the agricultural industry should concentrate on organic methods that mimic natures’ process rather than unsustainable inputs of fertilizers and pesticides. Local government and international bodies should promote widespread birth control and incentives to reduce population growth. We are part of a fragile ecosystem that requires more sustainable forms of development and a steady-state economy (Czech 2006) in order to prevent the further degradation of terrestrial ecosystems.
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