Conservation agriculture
Case studies in Latin America and Africa


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Table of Contents

Preface

Acknowledgements

Acronyms

Chapter 1 - Introduction

Chapter 2 - Concepts and impacts of conservation agriculture

Concepts

Changing mentalities

Combating land degradation and improvement of land productivity

Socio-economic advantages

Impacts on the environment

Chapter 3 - Rural communities actively implementing conservation agriculture

Organization: the role of farmers' groups and non-governmental organizations

Implementing conservation agriculture practices

Chapter 4 - Enabling community-based projects

Appropriate scenarios for conservation agriculture

Designing community-based projects: tools and practices

Involvement of all stakeholders

Institutional and policy considerations

Conservation agriculture linkages with international initiatives

Chapter 5 - Conclusions

References

Annex 1 - Key concepts and definitions

Annex 2 - The soil ecosystem

List of boxes

BOX 1: Principles of conservation agriculture

BOX 2: Key features of conservation agriculture systems

BOX 3: Agro-environmental features of conservation agriculture

BOX 4: Reasons for the slow research response to zero tillage in Brazil prior to 1995

BOX 5: Conservation structures and practices in Southern Brazil

BOX 6: Farmers' benefits - Lempira (Honduras)

BOX 7: Conservation of time and energy

BOX 8. The farmers' point of view - Lempira (Honduras)

BOX 9: Soil microbial communities and zero tillage

BOX 10: Nutrient availability under various cover crops (southern Brazil)

BOX 11: Carbon sequestration (southern Brazil)

BOX 12: Increase of protected areas through livestock management (Costa Rica)

BOX 13: Indigenous knowledge and empowerment in Africa

BOX 14: The Quesungual agroforestry system - Lempira (Honduras)

BOX 15: The Zero Tillage Association for the Tropics (ZTAT) - (Brazil)

BOX 16: Clubes Amigos da Terra (CAT) - (Brazil)

BOX 17: The Association for Better Land Husbandry (ABLH) - (Kenya)

BOX 18: Improved fallow with legumes

BOX 19: Improving conservation agriculture (southern Brazil)

BOX 20: The shifting cultivation systems (northern Brazil)

BOX 21: Conservation agriculture based on minimum tillage and animal production in East Africa

BOX 22: Crop selection for high residue production - Guaymango (El Salvador)

BOX 23: Better management and use of crop residues (northern Tanzania)

BOX 24: Improving soil fertility (southern Ethiopia)

BOX 25: Supporting farmers' land literacy (Zimbabwe)

BOX 26: Trash lines and banana mulching: farmers' innovations (Uganda)

BOX 27: The SADC-ICRAF Zambezi Basin Agroforestry Project

BOX 28: Conservation tillage technology transfer in KwaZulu

BOX 29: The Malawi Agroforestry Extension Project (MAFE)

BOX 30: Contribution of the Brazilian government to zero tillage promotion

BOX 31: History of a soil conservation law (Malawi)

BOX 32: Law 7779 "The use, management and conservation of soils" (Costa Rica)

BOX 33: The adoption process - Guaymango (El Salvador)

BOX 34: Sustainability through incentives; Paraná 12 meses - (Brazil)

BOX 35: The benefits of communal tenure

BOX 36: The African Conservation Tillage network (ACT)

BOX A1. Roles of the soil ecosystem

List of plates

Plate 1 - Continuous cultivation damages the vital but fragile ecosystem of soil flora and fauna, Bolivia.

Plate 2 - Soybean grown under conservation agriculture in Brazil

Plate 3 - Smallholder coffee farmers covering the soil with straw to preserve moisture, Malawi

Plate 4 - The use of tied ridges to catch and guide run-off and prevent damage to the crops

Plate 5 - Land preparation is by far the most time-consuming activity for the farmer and family

Plate 6 - Only a small percentage of the total area is worked in reduced tillage systems

Plate 7 - Flooding and sediment transport to the river increasing cost of water treatment

Plate 8 - The Quesungual system is an indigenous agroforestry system which most distinct characteristic is the combination of naturally regenerated and pruned trees and shrubs with more traditional agroforestry components, such as high value timber and fruit trees. In between the trees the traditional staple crops, i.e. maize, roghum and beans are grown

Plate 9 - Maasai, traditionally herding cattle, are engaging in vegetable growing activities to increase their income and spread the risks

Plate 10 - A historic moment: this meeting of farmers, technicians, and municipal leaders from Agrolandia, micro-catchment Ribeirao das Pedras, first discussed how to convert traditional animal traction equiment to direct-sowing equipment

Plate 11 - A Kenyan farmer in front of his Tithonia hedge, which is cut and used to fertilize his sukumawiki crop (Brassica sp.)

Plate 12 - Flowering wild sunflower, Tithonia, now a roadside weed in Kenya and the United Republic of Tanzania, which is used as green manure in western Kenya

Plate 13 - Implements have been adapted for resource-poor farmers: a herbicide spray, which can be drawn either manually or by animals

Plate 14 - The knife-roller bends over or crushes the cover vegetation, preparing the land for the succeeding crop, which will be sown through the residues

Plate 15 - Simple seed drill, which can cope well with the enormous amount of crop residues left in the field

Plate 16 - First introduction of an animal-drawn direct seeder in a Maasai village in northern Tanzania

Plate 17 - Stripping maize to separate palatable and non-palatable parts to be used respectively for animal fodder and soil improvement

Plate 18 - Drawings explaining box baling of maize stover

Plate 19 - Discussing and thinking about the future, and planning together

Plate 20 - Farmer explaining to his neighbours the functioning of a new implement

Plate 21 - Imitation of the erosive effect of rainfall on bare soil and on a soil covered with residues

Plate 22 - Banana mulching, a common practice to prevent soil moisture to evaporate and keeping the bananas productive for a longer period

Plate 23 - Free-roaming cattle often lead to conflicts between pastoralists and agriculturalists

Plate A2.1 - Earthworm casts contain up to four times more nitrogen than the surrounding soil, and earthworm burrowing activity improves water and air exchange within the soil

Plate A2.2 - Symbiotic bacteria, chiefly associated with leguminous plants and occurring in root nodules, enrich soils by adding nitrogen, a key plant nutrient. Nodules containing bacteria on the roots of a Vetch plant

List of tables

Table 1 - Common practices and consequences of conventional agriculture

Table 2 - Total area - in hectares - under no-tillage in different countries in the seventies, eighties and in1999/2000

Table 3 - Water, soil and plant nutrient losses under conventional agriculture and direct seeding in a wheat-maize rotation

List of figures

Figure 1 - Production increase of maize and sorghum under the Quesungual system

Figure 2 - Population sizeof rootnodule bacteria under zero tillage

Figure 3 - Maize production under the Quesungual system

Figure 4 - Yield of maize-sorghum system in Guaymango, 1963 - 1989

Figure 5 - Reduction in burning over the last 3 years in southern Lempira