Contour Stone Bunds for soil erosion control in the Sahel of West AfricaSahel

Background 1 2

High intensity rainfall is characteristic of large areas of the Sahel causing widespread rainfall runoff and erosion. Priority has therefore been given to a range of measures for run-off and soil erosion control. One such measure, the use of stone bunds built on natural contour lines, has been promoted and supported by governments, NGOs, extension agents and farmers for more than 25 years and is now widely used in the Sahel. The best results are often achieved when contour stone bunds are used in combination with the planting of grass and trees on the contour lines. In addition, where soils are particularly susceptible to surface crusting and runoff, farmers often combine contour stone bunds with ‘zai’ planting pits, which are 10-20 cm deep and act as micro-catchments into which crops are planted (Roose et al. 1999). 3

Relationship to CSA

Contour stone bunds are beneficial under both wetter and drier climate change scenarios. In wetter years they help to reduce the climate-induced risk of run-off and erosion. In drier years, they contribute to effective rainwater harvesting. In addition, since heavy rainfall events in the Sahel are projected to increase with global warming, durable and effective soil erosion control structures will assume even greater importance and constitute an important adaptation measure. In addition, when tree lines and/or grass strips are also planted on the contour, they have the potential to contribute to above and below ground soil carbon sequestration.

Impacts and lessons learned

Region-wide, it is estimated that about 300,000 ha of land has been reclaimed. However, contour stone bunds are labour intensive and costly. For example, between 1987 and 2006 in Burkina Faso, the PATECORE project supported the reclamation of over 100,000 ha of degraded land with 30,000 km of CBS. However, this required the quarrying and transport of 2.5 million cubic meters of stones at a net cost of US$ 200/ha and between 100-150 person days of unpaid farmer labor per hectare. Nevertheless, they have proven to be both highly effective and durable and often act as a catalyst for additional innovations such as tree or grass planting on the bunds, as well as increased levels of nutrient inputs on field crops.


  • 1

    Landolt M. 2011. Stone lines against desertification. Rural 21, January 2011. This brief provides farmer information and success stories on the practice of using stole contour lines to improve rainwater use and slow erosion in Burkina Faso.
  • 2

    Barry B, Olaleye AO, Zougmore R, Fatondji D. 2008. Rainwater harvesting technologies in the Sahelian zone of West Africa and the potential for outscaling. IWMI Working Paper 126. Colombo, Sri Lanka: International Water Management Institute. In West Africa, especially in the Sahelian countries of Burkina Faso, Niger, Mali, and Mauritania, erratic rainfall sequences within and between years has often led to a high uncertainty in rainfed crop production. Over the past three decades, severe food shortages attributed to drought have been frequently reported in several Sahelian countries, most of which are amongst the least developed of the world. The long dry periods affecting the majority of the arid and semi-arid countries in West Africa are associated with famine, displacement of populations, and loss of previously fertile land. One of the challenges of the Millennium Development Goals (MDGs) is to reduce poverty and hunger and ensure successful interventions are reported in rainfed agriculture in West Africa, which are transforming the livelihoods of many resource poor smallholder farmers. Innovative and indigenous ways to achieve improved crop yields through integrated land and water management such as rainwater harvesting and soil water conservation have been successfully tested and, in some cases, adopted in West Africa. This paper highlights the successful interventions of improved indigenous rainwater harvesting/soil water conservation technologies such as Zaï or tassa, stone rows and halfmoon in the Sahelian zones of West Africa over the past 10 years, and their contributions to enhancing food security and alleviating poverty. The potential for adoption of these technologies at the farm level and their outscaling to areas with similar agroecological zones are also discussed.
  • 3

    Roose E, Kabore V, Guenat C. 1999. Zai Practice: A West African Traditional Rehabilitation System for Semiarid Degraded Lands, a Case Study in Burkina Faso. Arid Soil Research and Rehabilitation 13(4):343-355. For degraded soil productivity, restoration, and green cover rehabilitation, it is essential to study and improve traditional farming systems, especially in the Sudano - Sahelian areas, where technical possibilities are limited. One example is the Zai practice, a very complex soil restoration system using organic matter localization, termites to bore channels in the crusted soils, runoff capture in microwatersheds, and seed hole cropping of sorghum or millet on sandy soils. Investigation on many fields of the Mossi Plateau (northern part of Burkina Faso) has shown a range of variations of the Zai system in relation to soil texture, availability of labor and organic matter, and relevance for rehabilitation of these degraded crusted soils. We describe a complex soil restoration system revealed during our 2 years of inquiries and experiments testing this system in two types of soil (a shallow, poor alfisol and a deep, brown tropical inceptisol). Biomass production of sorghum is reported in relation to various potential improvements of the Zai systems and also the wild grass and shrub species that appeared after 2-7 years of a Zai cropping system on a bare, crusted, degraded soil surface. Experimental improvements of this Za system on two soils confirm the possibility not only to increase the production of cereal grains (from 150 to 1700 kg ha-1) and straw (from 500 to 5300 kg ha-1) on deep, brown soils (eutropept), but also to reintroduce a large diversity of useful plants that may help during the fallow period and the process of degraded soil restoration. The concentration of runoff water, organic manure, and a complement of mineral nutrients in microwatersheds increased biomass production without significant change in soil properties after 2 years. This system may be useful not only to restore soil productivity but also for revegetation, e.g., 22 species of weeds and 13 species of forage shrubs included in dry dung manure (3 Mg ha-1 yr-1).

Welcometoclimate-smart agriculture 101

scroll to discover

This site is your gateway to implementing climate-smart agricultureIt will help you get started and guide you right through to implementation on the ground, connecting you with all the resources you need to dig deeper.

scroll to start

CCAFS Climate-Smart Agriculture 101

The basics

Climate-smart agriculture (CSA) is an integrative approach to address these interlinked challenges of food security and climate change, that explicitly aims for three objectives:

A. Sustainably increasing agricultural productivity, to support equitable increases in farm incomes, food security and development;

B. Adapting and building resilience of agricultural and food security systems to climate change at multiple levels; and

C. Reducing greenhouse gas emissions from agriculture (including crops, livestock and fisheries).

Entry points

Agriculture affects and is affected by climate change in a wide range of ways and there are numerous entry points for initiating CSA programmes or enhancing existing activities. Productivity, mitigation and adaptation actions can take place at different technological, organizational, institutional and political levels. To help you navigate these myriad entry points we have grouped them under three Thematic Areas: (i) CSA practices, (ii) CSA systems approaches, and (iii) Enabling environments for CSA. Each entry point is then described and analysed in terms of productivity, adoption and mitigation potential and is illustrated with cases studies, references and internet links for further information.

Develop a CSA plan

Planning for, implementing and monitoring CSA projects and programmes evolves around issues of understanding the context including identification of major problems/barriers and opportunities related to the focus of the programme; developing and prioritizing solutions and designing plans; implementation; and monitoring and evaluation. Most major development agencies have their own framework for project and programme formulation and management but CCAFS has developed a specific approach for planning, implementing and assessing CSA projects and programme called CSA plan. CSA plan was developed to provide a guide for operationalizing CSA planning, implementation and monitoring at scale. CSA plan consist of four major components: (1) Situation analysis; (2) Targeting and prioritizing; (3) Program support; and (4) Monitoring. evaluation and learning.


To meet the objectives of CSA, such as agricultural development, food security and climate change adaptation and mitigation, a number of potential funding sources are available. For instance, climate finance sources may be used to leverage agriculture finance and mainstream climate change into agricultural investments. This section offers an overview of potential sources of funding for activities in climate-smart agriculture (CSA) at national, regional and international levels and for a number of different potential ‘clients’ including governments, civil society, development organizations and others. Additionally, it includes options to search among a range of funding opportunities according to CSA focus area, sector and financing instrument.

Resource library

CSA Guide provides a short and concise introduction and overview of the multifaceted aspects of climate-smart agriculture. At the same time it offers links to references and key resources that allows for further investigations and understanding of specific topics of interest. In the resource library we have gathered all the references, key resources, terms and questions in one place for a quick overview and easy access that can be used as a part of or independently of the other sections of the website. The resource library is divided into six sections; (1) References – list all publications, links and blogs referred to on the website; (2) Tools – list all the CSA tools presented on the website; (3) Key terms – explains the most important and frequently used terms related to CSA; (4) Frequently asked questions (FAQ) – provides a rapid overview of the most common questions asked on climate-smart agriculture; (5) About – where you can find out more about the purpose and structure of, as well as on the organizations and authors behind the website; (6) Contact.

Case studies

Local case studies

Filter by entry points