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https://e-catalogs.taat-africa.org/gov/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 project

The Zaï Pit Implementation provides structured guidance for designing and scaling up the use of Zaï pits for land restoration and climate-resilient agriculture. It ensures a holistic approach by integrating financial, institutional, capacity-building, and technical aspects, making Zaï-based interventions sustainable, community-driven, and impactful. This framework helps governments, development organizations, and farming communities effectively adopt and expand the use of Zaï pits to enhance soil fertility, water retention, and agricultural productivity in dryland regions.

Steps for Effective Zaï Pit Implementation

  1. Define the Vision and Objectives

    • Establish clear goals for Zaï pit adoption, aligning with national priorities such as land restoration, food security, climate resilience, and sustainable dryland agriculture.
    • Ensure community engagement to enhance long-term adoption.

  2. Develop a Financial Sustainability Plan

    • Secure funding for training and implementation through government programs, NGOs, and climate adaptation funds.
    • Promote cost-effective scaling by supporting farmer-led initiatives and knowledge-sharing networks.

  3. Assess Capacity and Technical Needs

    • Identify the skills, training, and tools needed for effective Zaï pit construction and maintenance.
    • Train farmers, extension officers, and local organizations to facilitate knowledge transfer.

  4. Conduct a Needs Assessment

    • Engage farmers, agricultural experts, and policymakers to define key challenges and expected benefits.
    • Adapt Zaï pit designs based on local soil conditions, rainfall patterns, and cropping systems.

  5. Implement Data Collection and Governance Strategies

    • Establish monitoring systems to track yields, soil health, and water retention improvements.
    • Integrate Zaï-based soil restoration efforts into broader land management policies and climate action plans.

  6. Monitor and Evaluate Impact

    • Set up mechanisms to track the effectiveness of Zaï pit interventions using yield data, soil quality assessments, and farmer feedback.
    • Adjust strategies based on climate variability, farmer adoption rates, and ecosystem benefits.

By following these steps and leveraging the Zaï Pit Implementation, decision-makers can establish robust, scalable, and sustainable dryland farming solutions that drive land rehabilitation, food security, and climate resilience.

60 - 90 %

Yield Improvement

IP

Open source / open access

Tested & adopted
Adopted
Tested
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
Chad
Ghana
Mali
Mauritania
Niger
Nigeria
Senegal

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.

Downloads

Last updated on 5 March 2025

ICRISAT
Dr Dougbedji Fatondji
Commodities
Sorghum/Millet
Sustainable Development Goals Details ›
Sustainable Development Goal 1: no poverty
Sustainable Development Goal 2: zero hunger
Sustainable Development Goal 5: gender equality
Sustainable Development Goal 6: clean water and sanitation
Sustainable Development Goal 13: climate action
Sustainable Development Goal 15: life on land
+ 3 more
Category
Practices
Subcategory
Water management
Value chain step
Production
Solution
drought soil degradation
Tested/adopted in Details ›
Tested & adopted
Adopted
Tested
Testing ongoing
Where it can be used Details ›

This technology can be used in the colored agro-ecological zones.

Target groups
Farmers
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Zaï Pits: Water Harvesting and Soil Improvement

https://e-catalogs.taat-africa.org/gov/technologies/zai-pits-water-harvesting-and-soil-improvement

Last updated on 5 March 2025, printed on 28 March 2025

Enquiries e-catalogs@taat.africa