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You are here: Home Magazines Global edition Ecological processes at work

Ecological processes at work

last modified Jan 16, 2015 10:12 AM

In this issue of LEISA Magazine we present some examples of intensified agricultural production based on ecological processes.

These show how production can be intensified in a much more natural way, by changing our perceptions about agriculture and increasing our knowledge of ecological processes. At the same time negative environmental effects can be avoided and other benefits are gained along the way.

LEISA Magazine • 22.4 • December 2006

Table of contents:

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    Agriculture is based on the same ecological processes, interactions and ecosystem services that occur in the natural environment – although this fact sometimes appears to have been forgotten in the drive to industrialise agriculture over the past half century. The ecological processes and the delivery of ecosystem services in nature are underpinned by a rich diversity of organisms, adapted to each other and making use of all possible niches in the physical environment. These processes can be positively or negatively influenced by human activities. Good examples of positive influences include some traditional agricultural systems, governed by an intimate understanding of local conditions and respect for the living environment.
  • 6 - 8
    The System of Rice Intensification (SRI) reported on by several other contributors to this and previous issues of the LEISA Magazine is casting new light upon both “modern” agriculture and agroecological alternatives. Just because something is widely believed or practised does not necessarily make it true or optimal. Keeping our minds open to new evidence and new ideas is essential for faring well in the contemporary world.
  • 9 - 11
    Agroecology provides guidelines for developing diversified agroecosystems that take advantage of the integration of plant and animal biodiversity. Successful integration of plants and animals can strengthen positive interactions and optimise the functions and processes in the ecosystem, such as the regulation of harmful organisms, recycling of nutrients, biomass production and the build up of organic matter. In this way agroecosystems can become more resilient. Farmers need to identify and support processes that strengthen the functioning of the agroecosystem.
  • 12 - 13
    Groups of farmer experimenters in the state of Santa Catarina in southern Brazil have been experimenting with different techniques to manage the soil fertility in their fields. One method they have been testing is the use of powdered rocks mixed with different sources of biomass, which has proved successful in revitalising the soils. This method is not about substituting inputs (substituting chemical fertilizers for powdered rock) but involves a change in the way we think about soil fertility management in an agroecosystem. Their results have been very interesting, and the process has also increased their understanding of some ecological processes important in soil fertility management.
  • 14 - 15
    In the Northern Province of Zambia, many small scale farmers practise shifting cultivation (known locally as chitemene) in the miombo woodlands. Though farmers are able to grow an average of three successive crops under this practice, soil fertility and crop yields decline after the third year, meaning that farmers have to open new fields. Studies have shown that the chitemene system can be sustained so long as the population density does not exceed seven persons per square kilometre. However, with improvements in health and nutrition, rural populations have been growing. Farmers are no longer able to wait for up to 25 years, the length of time fields were traditionally left fallow to restore their natural fertility, before returning to fallowed fields. They now wait around 10 years. This has led to a breakdown in the effectiveness of the chitemene system.
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    Soil fertility management is a key issue for sustaining agricultural production in the tropics. Organic resources are important for short-term nutrient availability, as well as for longer-term maintenance of soil organic matter. For smallholder farmers, organic materials are an important source of nutrients, and necessary to manage soil fertility. However, the amount of organic material available on-farm is often limited in supply, and differs widely in quality. This is why the little that is available needs to be used as efficiently as possible.
  • 18 - 19
    Conservation Farming takes advantage of natural ecological processes to conserve moisture, enhance soil fertility, and improve soil structure, and to reduce soil erosion and the presence of diseases and pests. It does this in three main ways – through minimal soil disturbance, the retention of crop residues and crop rotation. Ploughing and burning disturb the soil and the micro-biota that live there. In contrast, Conservation Farming involves very little soil disturbance, enabling naturallyoccurring soil flora and fauna to flourish.
  • 20 - 21
    The Chittagong Hill Tracts in Bangladesh differ in many respects to the rest of the country. A mountainous area, it is geographically part of the Hindu Kush-Himalaya region. Demographic and environmental conditions have changed drastically in the last decades, mainly as a result of the dam built on the Karnafuli River (which inundated more than 20 000 hectares of cultivated land) and twenty years of armed conflict that ended in 1997. These changes, together with the scarcity of suitable land, have meant that the traditional slash and burn farming system locally known as jhum has become unsustainable. Combined with other factors, such as forest overexploitation, it is one cause of increased land degradation, resulting in diminishing yields and decreased biodiversity.
  • 22 - 23
    Shade coffee agroecosystems have exceptional potential for the conservation of tropical plant and animal species, in addition to producing high quality coffee. This article shows how this potential is linked to the farmers’ livelihood strategies in six co-operatives of El Salvador and Nicaragua. The use of a Participatory Action Research approach facilitated the exchange of information between researchers and farmers. This mutual learning process helped to increase understanding of the ecological processes in shade grown coffee. This greater understanding has made it possible to develop better management practices (specifically in terms of soil fertility, pest and weed management), supporting the co-operatives and the livelihoods of their members.
  • 24 - 24
    Coffee production in the state of Chiapas, Mexico, is a means of survival for many indigenous farmers. Since the early 1990s, when government loans for fertilizer dried up, most small-scale farmers in this state have not been able to afford synthetic fertilizers or pesticides. This, together with declining yields, soil quality, and personal health, has encouraged many farmers to revert back to chemical-free coffee production systems. To increase profits, they began certifying their farms as organic. Since organic coffee producers are restricted from using agrochemicals, they depend heavily upon soil management techniques to provide the necessary nutrients to their crop. We investigated the farmers’ knowledge of these processes through in-depth interviews with groups of organic farmers with different lengths of experience as organic farmers.
  • 25 - 27
    Rice is the crop which contributes most to Nepal’s national economy and is the main staple food for its people. But despite a lot of investment and efforts, the productivity of rice in Nepal has remained the lowest within this region. This situation encouraged some development workers to begin testing the System of Rice Intensification (SRI) in 2001, and after a few years of effort by different organisations and individuals, SRI is now becoming popular and establishing its position within the mainstream of agricultural development in the country. This article describes how this was achieved, discusses some of the challenges faced, and shows that for individual farmers, rice cultivation by SRI methods is becoming increasingly attractive due to its greater profitability compared with conventional methods.
  • 28 - 29
    Tamil Nadu is India’s southernmost state. About two million hectares of rice is grown, mostly under irrigation, with an average yield of 5 t/ha. Average rice productivity is the highest in the country. There is consensus, however, about the need to improve production, as water shortages are becoming increasingly severe, and overall production has stagnated in recent years. The System of Rice Intensification, or SRI, was introduced only five years ago, and is currently the subject of much debate among agricultural scientists. But farmers are adopting it without bothering about the controversies raised. This is basically because of the visible results that SRI farmers achieve. By employing different principles which includes younger seedlings and wider spacing, SRI offers higher yields and incomes, lower cultivation costs, and other benefits. This article describes these principles on the basis of the experiences of farmers in this state.
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    The development of the System of Rice Intensification (SRI) over the past two decades has generated a variety of responses from farmers and scientists. These responses are illustrative of the gap that exists between the conventional policies and attitudes towards agricultural research and development, and the agricultural development taking place in the field. This highlights the need for scientists and development personnel to consider a much broader range of technologies than the conventional modern technological packages that are widely promoted as the only means of resolving the world food problem.
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    SRI is a promising option for addressing the problem of limited water availability. However, any solution needs to consider more than just the technical aspects.
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    CBIK is a Chinese NGO based in Yunnan province. Established in 1995, it currently has 22 staff, and more than 100 members. CBIK is dedicated to promoting the sustainable utilisation of biodiversity to support livelihoods among ethnic minority peoples in Yunnan and southwest China. The main way we seek to achieve this is by doing action-research with ethnic minority communities, the government and other non-government agencies. CBIK is known within China as one of the early practitioners and promoters of participatory approaches, such as Participatory Technology Development, which have been applied in agriculture, animal husbandry and forestry. CBIK also serves as a centre for information exchange on issues relating to livelihoods and resource management in ethnic minority areas of southwest China. It has produced several dozen Chinese language publications, and convened national and international meetings that promote exchange and collaboration on relevant issues.
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