[permaculture] fwd: Sustainable Agriculture Pushing Back the Desert

Henne, Adam hennea at highbridgelife.org
Wed Mar 27 12:46:42 EST 2002


>From: Mitch Stargrove <Mitch at DANCINGDNA.COM>
>Reply-To: Health and  Environment Resource Center              
><HEALTHE at MAELSTROM.STJOHNS.EDU>
>To: HEALTHE at MAELSTROM.STJOHNS.EDU
>Subject: [HEALTHE] fwd: Sustainable Agriculture Pushing Back the Desert
>Date: Mon, 25 Mar 2002 22:24:30 -0800
>
>Sustainable Agriculture Pushing Back the Desert
>
>Desertification - land degrading into desert - is often blamed on
>mismanagement and misuse of land. Local people are allegedly guilty
>of over-farming, over-grazing and allowing their populations to
>exceed the environment's capacity. <mailto:ching at i-sis.org.uk>Lim Li
>Ching contests this myth, describing how local farmers in arid Africa
>are using innovative means to farm productively without destroying
>the environment, and highlights some criteria for sustainable
>agriculture.
>
>If you wish to see the
><http://www.i-sis.org.uk/full/desertificationFull.php>complete
>document with references, please consider becoming a member or friend
>of ISIS. Full details <http://www.i-sis.org.uk/membership.php>here
>
>Debates concerning natural resources often pivot on a 'received
>wisdom' about environmental change and people's role in this process.
>In the case of the environment, the received wisdom is that people
>invariably degrade natural resources. Outsiders, perceiving
>environmental change as degradation, blame local land-use practices.
>
>The dominant idea about desertification has been that dryland
>environments are rapidly degraded by a combination of natural and
>human factors. Desertification is defined as the degradation of
>drylands, involving loss of biological or economic productivity and
>complexity.
>
>From the 1930s, the blame was laid largely on the land use practices
>of farmers and herders, and on increasing populations. This was
>reinforced in the late 1970s and early 1980s, culminating in the UN
>Conference on Desertification in 1977. Some scientists were uncertain
>about the causes and extent of desertification, and expressed concern
>at the lack of long-term data. Despite that, the Conference ended by
>stating that desertification was threatening 19% of the earth's
>surface, and that this threat came from increased intensity of land
>use, overgrazing and inappropriate irrigation, exacerbated by drought.
>
>Such claims were reiterated by the UN Environment Programme, which
>was the driving force for the UN Convention to Combat Desertification
>(UNCCD), which entered into force in 1996. The rationale for the
>Convention is that "over 250 million people are directly affected by
>desertification, and some one thousand million (or one billion) are
>at riskS. Over the past two decades, the problem of land degradation
>in dryland regions has continued to worsen".
>
>Yet, evidence has been mounting that some of these assertions are
>unfounded. Most received wisdom on 'desertification' and 'land
>degradation' assumes an equilibrium environment with linear
>development. Thus, observations of expanding desert at certain
>periods and certain locations are extrapolated as ongoing, even
>accelerating, desertification.
>
>For instance, work in northern Sudan that estimated the desert edge
>had shifted 90-100 km southwards in 17 years, is often cited. Whilst
>the period and location of the study was limited, it produced
>widespread understanding that "the whole southern Saharan edge" was
>expanding at a rate of 6 km a year. These results were later
>disproved.
>
>In the first instance, there are in effect three related but distinct
>phenomena - drought, dessication and dryland degradation - that have
>been conflated in the term 'desertification'. On a continuum, these
>have increasing time-scale effects and decreasing potential for
>recovery.
>
>In particular, drought pulses are now seen as a key driving force of
>dynamic ecological systems - droughts lead to variability in
>ecosystem process and productivity, not its decline. And in many
>cases, what was assumed as dryland degradation is actually a result
>of drought, and can reverse quickly under normal rainfall.
>Additionally, data from dry years were often compared with that from
>wet years, ignoring longer-term climatic cycles. This led to an
>interpretation of a decline in productivity, rather than a variation
>in the response of natural vegetation or crops to soil moisture
>availability.
>
>The new understanding is that arid and semi-arid areas are
>non-equilibrium environments, characterised by high levels of
>temporal and spatial variability and therefore, are unpredictable and
>uncertain. The critical indicator is a high coefficient of variation
>in rainfall (30% or more). Rainfall doesn't follow regular patterns,
>at least not in the short-term, and it affects variability of
>patterns and amount of vegetation.
>
>This dynamic conception of drylands is underpinned by changes within
>ecological thinking - the 'new ecology' - that have suggested that
>nature is in a state of continuous change. It contests conventional
>ecology, which depicts nature as tending toward stability, with
>notions of 'carrying capacity' and assumptions of a stable climax at
>equilibrium i.e. if the carrying capacity is exceeded, deterioration
>occurs.
>
>The 'new ecology' also involves a conception of historical time. Land
>that appears 'degraded' may have already been that way long before
>farming or grazing. Researchers might erroneously associate degraded
>land with destructive human activity while knowing little of a
>place's environmental history.
>
>Dynamic ecological systems mean that ecological drivers are external
>in dryland environments, and hence not necessarily subject to
>density-dependent events. Instead, human livelihood adaptations in
>these environments are very specialised; people are in reality
>raising meat and crops under ecologically sound conditions.
>
>New research reveals that in many of the poorest African countries
>along the Sahara's edge, in Nigeria, Niger, Senegal, Burkina Faso and
>Kenya, integrated farming, mixed cropping and traditional soil and
>water conservation methods are increasing per capita food production
>several fold, keeping well ahead of population growth.
>
>For example, the use of sheep manure for fertiliser has allowed
>increased yields for farmers in Kano, Nigeria. Additionally, planting
>leguminous crops increases nutrient levels in the soil by fixing
>nitrogen from the air. Integration of crops and livestock enhances
>nutrient cycling - legumes and manure return to the soil what crops
>take out.
>
>A 4-year study in eastern Burkina Faso found that despite declining
>rainfall since the late 1950s and increasing populations, there is no
>evidence of land degradation connected to human activities nor a
>decline in food productivity. Conversely, yields of many crops have
>risen. The study found no proof of soil fertility decline over 30
>years.
>
>Farmers have not achieved environmental sustainability through a
>capital-intensive or high-tech path. In Burkina Faso, the increased
>yields of sorghum, millet and groundnuts is hardly attributable to
>increased external inputs, because these crops receive little
>fertiliser and are largely based on hand hoe cultivation.
>
>Farmers have a rich repertoire of soil and water conservation
>technologies, such as crop sequencing, crop rotation, fallowing,
>weeding, selective clearing, intercropping, appropriate crop &
>landrace selection, adapted plant spacing, thinning, mulching,
>stubble grazing, weeding mounds, paddocking, household refuse
>application, manure application, crop residue application and compost
>pits. They use many mechanical practices too.
>
>Perhaps more important than the practices is the selective way they
>are used, which vary with different field types, allowing optimal
>adjustment of limited labour and inputs to the requirements of
>different crops and soils. If land becomes limited, farmers do not
>need to invent new management systems; they apply these soil and
>water conservation practices more intensively, and only when and
>where needed.
>
>High local population densities, far from being a liability, are
>actually essential for providing the necessary labour to work the
>land, dig terraces and collect water in ponds for irrigation, and to
>control weeds, tend fields, feed animals and spread manure. As
>population densities increase, farmers intensify their cooperation
>systems, grouping to tend each other's fields at busy periods,
>lending and borrowing land, livestock and equipment, and swapping
>seed varieties.
>
>People thus invest heavily in creating and maintaining social
>networks, such as land networks, labour networks, women's natal
>networks, cattle networks, technology networks and cash networks.
>
>Furthermore, in Maradi district in southern Niger, where repeated
>droughts have wrought environmental damage, farmers have been
>fighting back, and have actually reversed desertification. This is
>also true of Machakos (renamed Makueni) district in Kenya. In the
>1930s, British colonial scientists condemned the eroding, bare hills
>of the drought-prone area to environmental oblivion. This narrative
>was consistently reproduced in the 1950s and 1970s. Yet, while there
>have been droughts, the hills are greener, less eroded and more
>productive today than before, despite a fivefold population increase.
>The local Akamba people had responded to the droughts by switching
>from herding cattle to settled farming, giving them incentive to work
>the land effectively.
>
>"This is no high-tech breakthrough, nor a result of Western aid
>programmes". A major reason for the overestimation of land
>degradation is the underestimation of local farmers' abilities.
>
>This demonstrates the importance of relying and building on local
>people's knowledge and practices. Many external interventions have
>usurped and undermined local systems of decision-making and resource
>management. It's time to turn the received wisdom on its head, and
>learn from local communities, instead of blaming them wholesale for
>land degradation.
>
>In light of all this evidence, a 'new realism' now exists about
>desertification, which gives climatic variation equal footing with
>human activities, as a cause. The UNCCD now takes care to point out
>the reversibility of drought, the influence of climatic variation,
>and recognises that the causes of desertification are complex, as is
>the human-environment relationship.
>
>Policies need to appreciate the inherent uncertainty in science.
>'Opportunistic management', i.e. seizing opportunities to evade
>problems, working within complex systems, adapting to instability and
>exploiting environmental instability, is needed for dynamic
>ecosystems.
>
>Dynamic ecological theory does not replace conventional theory but is
>more appropriate in some contexts, such as in dryland ecosystems.
>Environmental complexity doesn't lend itself to simple, linear or
>reductionist technological fixes. Ecosystems are dynamic wholes and
>sustainable agriculture works in tandem with these (see Box), as
>local farmers in Africa are showing.
>
>Sustainable agriculture
>
>makes best use of nature's goods and services by integrating natural,
>regenerative processes e.g. nutrient cycling, nitrogen fixation, soil
>regeneration and natural enemies of pests
>minimises non-renewable inputs (pesticides and fertilisers) that
>damage the environment or harm human health
>relies on the knowledge and skills of farmers
>promotes and protects social capital - people's capacities to work
>together to solve common management problems
>depends on locally-adapted practices to innovate in the face of uncertainty
>contributes to public goods, such as clean water, wildlife, carbon
>sequestration in soils, flood protection and landscape quality
>If you wish to see the
><http://www.i-sis.org.uk/full/desertificationFull.php>complete
>document with references, please consider becoming a member or friend
>of ISIS. Full details <http://www.i-sis.org.uk/membership.php>here
>
>
>This article can be found on the I-SIS website at
><http://www.i-sis.org.uk/desertification.php>http://www.i-sis.org.uk/desert
ification.php
>
>The Institute of Science in Society <http://www.i-sis.org.uk/>
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>
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