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https://e-catalogs.taat-africa.org/org/technologies/zai-pits-water-harvesting-and-soil-improvement
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Zaï Pits: Water Harvesting and Soil Improvement

Zaï pits are an ancestral water-harvesting technique used in the Sahel to rehabilitate degraded lands. Farmers dig small basins (20–40 cm in diameter and 10–20 cm deep) during the dry season to trap rainwater, soil particles, and organic matter. Between 12,000 and 25,000 pits per hectare are typically dug, with excavated soil placed downslope to capture additional runoff. Each pit is enriched with organic matter (compost, manure, or straw) and mineral fertilizers (5–6 g of NPK or DAP per pit, totaling 72–144 kg per hectare). Millet or sorghum seeds are then planted at the center of the pit. This method enhances water infiltration, retains nutrients, and improves soil structure, ensuring better crop performance in arid environments. Zaï pits can be combined with other dryland techniques like stone bunds, half-moon structures, and tied ridges to maximize land restoration and agricultural productivity.

2

This technology is TAAT1 validated.

Scaling readiness: idea maturity unknown; level of use unknown

Adults 18 and over: Positive high

Increases food security and income for farming households by improving crop yields.

The poor: Positive medium

Requires minimal external inputs, making it affordable for resource-poor farmers. Increases food availability and reduces reliance on expensive fertilizers.

Under 18: Positive low

Youth can participate in land preparation, learning traditional farming techniques. However, labor intensity may discourage engagement.

Women: Positive medium

Women, who are often responsible for food production, benefit from improved soil fertility and yields. However, the labor-intensive nature of Zaï pits may pose challenges unless supported by community-based labor-sharing initiatives.

Climate adaptability: Highly adaptable

Increases resilience to droughts by improving water retention and soil fertility.

Farmer climate change readiness: Significant improvement

Encourages sustainable land management, reducing vulnerability to climate shocks.

Biodiversity: Positive impact on biodiversity

Can support soil microorganisms and plant diversity if combined with agroforestry or intercropping.

Carbon footprint: Much less carbon released

Enhances soil organic matter storage, contributing to carbon sequestration.

Environmental health: Greatly improves environmental health

Reduces soil erosion, prevents land degradation, and enhances ecosystem services.

Soil quality: Improves soil health and fertility

Improves soil structure, nutrient content, and organic matter levels.

Water use: Much less water used

Increases rainfall infiltration and reduces runoff, making better use of available water.

Problem

  • Low rainfall and frequent droughts in the Sahel reduce crop yields and threaten food security.
  • Soil degradation and crust formation limit water infiltration and plant growth.
  • Nutrient-poor soils hinder crop productivity, making farming unsustainable.
  • Runoff and erosion lead to further soil loss and reduce available moisture for crops.

Solution

Zaï pits enhance water retention and soil fertility in drylands by using a micro-catchment system. This technique:

  • Increases crop resilience by improving moisture availability during dry periods.
  • Boosts yields by 60–90% for millet and sorghum compared to flat cultivation.
  • Restores degraded lands, making marginal soils productive again.
  • Optimizes local resources by incorporating organic and mineral fertilizers.
  • Is cost-effective and easy to adopt, requiring only manual labor.

Key points to design your program

Zaï Pits are a traditional water harvesting and soil restoration technique that uses small planting pits to capture rainfall, improve water infiltration, and concentrate organic and mineral nutrients around crop roots. By restoring degraded soils, reducing runoff, and improving moisture availability during dry periods, the technology increases the productivity and resilience of millet and sorghum production in drought-prone environments. It is well suited for climate-smart agriculture, sustainable land management, dryland restoration, and food security programmes, contributing to SDGs 1 (No Poverty), 2 (Zero Hunger), 13 (Climate Action), and 15 (Life on Land). The technology provides significant benefits for smallholder farmers by restoring degraded land, improving resource-use efficiency, and increasing agricultural productivity with locally available resources. To successfully integrate this technology, consider the following key actions :

  • Identify drought-prone and degraded production areas where low rainfall, poor soil fertility, runoff, and soil crusting limit crop productivity.
  • Establish partnerships with national research institutions, extension services, community organizations, and local authorities to support the dissemination of Zaï technology and sustainable land restoration practices.
  • Facilitate access to organic matter, mineral fertilizers, and simple hand tools required for Zaï pit establishment and maintenance.
  • Strengthen technical capacity by training farmers, extension agents, and community groups on Zaï pit construction, nutrient management, water harvesting, and integrated soil fertility management.
  • Promote integrated land restoration practices by combining Zaï pits with organic amendments, agroforestry, stone bunds, or other soil and water conservation measures adapted to local conditions.
  • Promote the participation of women and youth through community-based land restoration initiatives and improved access to technical knowledge and productive resources.
  • Monitor programme performance through indicators such as restored land area, crop productivity, soil moisture retention, adoption rates, and the participation of women and youth.

60 - 90 %

Yield Improvement

IP

Open source / open access

Enabling Environments for Sustainable Regional Agriculture Extension (ENSURE)

  • Project funder: African Development Bank & East Africa Community

  • Planned Budget: USD 13.14 million

  • Location: East African Community (Burundi, DRC, Kenya, Rwanda, South Sudan, Tanzania, Uganda)

  • Planned duration: 2024–2027

  • Deployment means: On-farm demonstrations, training, digital tools (SMS, IVR, video, radio, pictorial guides), bundled inputs + advisory services, Training of Trainers (ToT)

  • Project main implementer: East African Community (EAC)

  • Project Description: Strengthen agricultural extension systems using digital tools, private-sector approaches, regional coordination, and multi-commodity focus (maize, cassava, rice, drought-resilient crops).

  • Objective: Promote regional extension, enhance advisory services, scale climate-smart technologies, build sustainable private sector–led extension systems, strengthen policy and regulatory frameworks.

  • Expected outcome: Increased adoption of improved technologies, improved farmer productivity and profitability, enhanced access to quality inputs and pest management solutions, strengthened resilience to climate and pest risks, regional market integration, job creation for youth and agripreneurs.

  • Figures of adoption: Target 3 million farmers reached over 4 years, digital extension pilots in 7 EAC states, training of extension agents, lead farmers, cooperatives, and youth agripreneurs, rollout of Pest Information Management Systems (PIMS).

  • Profiles of adopters: Smallholder farmers, women, youth agripreneurs, cooperatives and producer organizations, public and private extension agents, National Plant Protection Officers (NPPOs).

  • Lessons learnt: System-level approaches needed beyond technology delivery, digital tools most effective with in-person facilitation, supportive policy/regulatory environment critical, regional harmonization boosts scalability and cross-border diffusion of technologies. 

Countries with a green colour
Tested & adopted
Countries with a bright green colour
Adopted
Countries with a yellow colour
Tested
Countries with a blue colour
Testing ongoing
Egypt Equatorial Guinea Ethiopia Algeria Angola Benin Botswana Burundi Burkina Faso Democratic Republic of the Congo Djibouti Côte d’Ivoire Eritrea Gabon Gambia Ghana Guinea Guinea-Bissau Cameroon Kenya Libya Liberia Madagascar Mali Malawi Morocco Mauritania Mozambique Namibia Niger Nigeria Republic of the Congo Rwanda Zambia Senegal Sierra Leone Zimbabwe Somalia South Sudan Sudan South Africa Eswatini Tanzania Togo Tunisia Chad Uganda Western Sahara Central African Republic Lesotho
Countries where the technology is being tested or has been tested and adopted
Country Testing ongoing Tested Adopted
Burkina Faso Testing ongoing Tested Adopted
Chad Testing ongoing Tested Adopted
Ghana Testing ongoing Tested Adopted
Mali Testing ongoing Tested Adopted
Mauritania Testing ongoing Tested Adopted
Niger Testing ongoing Tested Adopted
Nigeria Testing ongoing Tested Adopted
Senegal Testing ongoing Tested Adopted

This technology can be used in the colored agro-ecological zones. Any zones shown in white are not suitable for this technology.

Agro-ecological zones where this technology can be used
AEZ Subtropic - warm Subtropic - cool Tropic - warm Tropic - cool
Arid
Semiarid
Subhumid
Humid

Source: HarvestChoice/IFPRI 2009

The United Nations Sustainable Development Goals that are applicable to this technology.

Sustainable Development Goal 1: no poverty
Goal 1: no poverty

Enhances agricultural productivity, increasing incomes for smallholder farmers.

Sustainable Development Goal 2: zero hunger
Goal 2: zero hunger

Improves food security by increasing millet and sorghum yields in drylands.

Sustainable Development Goal 5: gender equality
Goal 5: gender equality

Supports women farmers but may require gender-sensitive labor-sharing mechanisms.

Sustainable Development Goal 6: clean water and sanitation
Goal 6: clean water and sanitation

Reduces water runoff and enhances local water retention.

Sustainable Development Goal 13: climate action
Goal 13: climate action

Improves climate resilience and supports adaptation to droughts.

Sustainable Development Goal 15: life on land
Goal 15: life on land

Prevents land degradation, restores soil health, and supports sustainable land use.

1. Site Selection and Preparation

  • Choose a degraded or low-productivity field with compacted or crusted soil.
  • Clear the land of large debris, rocks, and weeds before digging.

2. Digging the Pits

  • Dig small basins (zaï pits) of 20–40 cm in diameter and 10–20 cm deep during the dry season.
  • Arrange the pits in a staggered pattern across the field.
  • Ensure a density of 12,000–25,000 pits per hectare, depending on soil type and slope.
  • Place the excavated soil downslope of each pit to help trap additional runoff.

3. Adding Organic and Mineral Fertilizers

  • Apply two handfuls of organic matter (compost, decomposed manure, or cereal straw) in each pit to enhance soil fertility and water retention.
  • Add 5–6 g of NPK or DAP fertilizer per pit (equivalent to 72–144 kg per hectare) and mix it with the soil at the base.

4. Sowing the Seeds

  • Plant millet or sorghum seeds at the center of each pit at the recommended depth.
  • Ensure proper seed spacing for optimal growth.

5. Maintenance and Management

  • Regularly monitor the pits to remove weeds and replenish organic matter as needed.
  • After the rainy season, repair or deepen pits that have filled with silt to maintain effectiveness.
  • Over time, integrate other soil conservation methods (e.g., stone bunds, half-moons) to enhance land restoration.

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Last updated on 3 July 2026