Increased soil degradation is threatening food security and the livelihood of millions of farm households throughout the world. In developing countries, one of the primary causes is intensive soil preparation by hoe or plough which, together with the removal or burning of crop residues, leaves soils exposed to climatic hazards such as rains, wind and sun. 

In contrast, the practice of "conservation tillage" - a term which embraces all practices that minimise soil disturbance and contribute to a sustained use of agricultural soils - changes, reduces or eliminates tillage operations and leaves a cover of crop or other plant residues, thereby reducing soil disturbance and protecting the soil from wind and water erosion. Conservation tillage therefore has an enormous potential for contributing to sustainable food production on a global scale at relatively low cost. 

While direct planting through a permanent soil cover seems to be the optimal system, it tends to be limited to humid tropics with a high biomass production. In dryer regions, especially where natural pastures are insufficient to support domesticated livestock, crop residues are frequently insufficient for classical 'no-till' systems, and alternative systems involving reduced or minimum tillage need to be developed. 

Conservation tillage practices are being increasingly utilised in many parts of the world, especially in North and South America, where a substantial percentage of agricultural land is no longer ploughed. In Africa the understanding that current cropping practices are not sustainable is widespread, and the consequent development and adoption of various conservation tillage systems proliferating throughout the continent. 

To facilitate the exchange of ideas and findings within Africa, and by and between African conservation tillage practitioners and promoters and their counterparts in other parts of the world, FAO, GTZ, ARC, FARMESA and ZFU convened a workshop entitled "Conservation Tillage for Sustainable Agriculture". Held in Harare, Zimbabwe from 22 to 27 June 1998, the 80 participants included practitioners, extensionists, researchers, agricultural administrators and agribusiness representatives from over 14 African countries as well as the Americas, New Zealand and Europe. 

Local host the Zimbabwe Farmers Union (ZFU) ensured the workshop received the prominence a subject so vital to the survival of the continent warranted. The workshop was opened by the Minister of Agriculture and closed by the Minister for Mines, Environment and Tourism, both Ministers endorsing conservation tillage. 

The overall objective of the workshop was to enhance the adoption of conservation tillage through the exchange of existing knowledge and by the initiation of partnerships between national and regional stakeholders. The workshop was divided in two parts, objectives of the first part being: 

• To establish an inventory of the technologies and approaches in use in different regions and countries;
• To identify factors contributing to the success and failure of conservation tillage adoption;
• To determine methods whereby conservation tillage options can be successfully disseminated;
• To develop national and regional action plans.
• The second part addressed specifically the development of international guidelines for environmentally sound tillage practices for the protection of soil. All participants were invited to attend the first part, and the international experts and country policy representatives were asked to participate in the second part. It was, however, open to all interested participants, and about 25 attended.

Discussions on technological issues indicated that a wide range of conservation tillage technologies have been developed. A number of constraints are, however, hindering the spread of these technologies, including inadequate dissemination, lack of capital, perceptions that adoption involves high risk, poor managerial skills, insecure land tenure systems and weed control. 

Strategies to overcome these constraints included the use of cover crops to increase biomass levels, awareness campaigns, generation of appropriate technologies through participatory technology development, improving support services through agri-business entrepreneurs, and reviews of land tenure policy. Strong feelings were expressed during group discussions that the transition from conventional practices to true conservation tillage could not be achieved overnight. 

There were two different points of view about technology transfer. One group, including representatives of agribusiness and an NGO, felt technologies available were adequate and should be promoted as a 'high tech package'. The other group tended to prefer the offer of system component alternatives for prospective user on-farm testing and adoption. After some discussion, however, the workshop agreed that the diverse nature of farming conditions in Africa requires the use of holistic and participatory approaches to ensure appropriate conservation tillage system adoption and ownership. 

Lessons learnt from countries where conservation tillage use is most advanced, such is in south Brazil, suggested that the empowerment and innovation of farmers is critical for conservation tillage adoption. Other components of importance included the testing and altering of equipment, the use of herbicides and/or cover crops or rotations to control weeds, and the adoption and promotion of effective soil conservation policies, without which conservation tillage adoption in the southern and eastern African region may remain a dream, particularly in the smallholder farming sector. 

Towards the end of the workshop, participants met in country groups to elaborate on individual and country-based action plans. From the list of activities that were generated in the workgroups, participants committed themselves to certain activities to strengthen the dissemination and adoption of conservation tillage in their countries. 

Progress was made toward the preparation of steps leading to a regional action plan to support conservation tillage in Africa by sharing regional and worldwide experience in conservation tillage and extracting lessons learned for possible application in Sub-Saharan Africa. A regional network could serve this purpose. Suggestions on the mode of operation of a potential network were made and country liaison persons nominated. To avoid duplication an inventory of existing networks was initiated, and a working group mandated to work out the terms of reference of a future network. 

An important output of the workshop was the initiation of the International Guidelines on Conservation Tillage for Sustainable Agriculture. Designed to serve government and international agencies, NGO’s, agri-business and other research, development, extension, education, training and policy-making organisations which can affect the development, transfer, and adoption of Conservation Tillage by farmers, it is hoped that this document will not only provide a valuable guide to farmers, but could also provide the framework for international and country policies which will ensure the promotion and adoption of conservation tillage throughout the world. 

 Table of Contents