Half-moon Pits are water harvesting techniques that assists crop growth in harsh climatic conditions, improving water and nutrient availability, promoting biodiversity and restoring the fertility of the degraded soil. The technique is similar to Zai pits in terms of its purpose. Half-moons are semi-circular wide-open basins used to collect runoff water. The mouth of the half-moons must face a slope where rainwater will flow during precipitation events. Water will be trapped in the pit to irrigate crops. Stones are used to support the half-moon curve to avoid being washed away during rain. The amount of fertilisers required in farming systems decreases when this technique is adopted by farmers. Areas with lots of rainfall are not suitable for this technique as it may lead to water logging effect.
To effectively implement Half-moon techniques, the following steps should be carried out:
- Step 1: Farmers should consider the diameter of the half-moon between 2 m – 3 m, with a total surface area of approximately 1.5 sqm and 3.5 sqm.
- Step 2: Pits should be dug to a depth of between 15 cm to 30 cm.
- Step 3: Excavated material can be piled around the curved section of the half-moon.
- Step 4: The curved section of the half-moon can be reinforced by stones to prevent washouts of the half-moon.
- Step 5: 35 kg of organic fertilisers/compost should be evenly distributed in the half-moon.
- The Food and Agriculture Organisation (FAO), 2017. Impact of agroecological techniques on soil fertility and productivity of sorghum and pearl millet in Burkina Faso. Rome, Italy.
- The Food and Agriculture Organisation, (FAO), 2018. Climate-Smart Agriculture, Training Manual. Rome, Italy.
Benefits
- Pits are left to sit while fertiliser/compost material converts to productive soil material.
- Half-moons allow for nutrient concentration and water infiltration that provides improved conditions for crops to grow.
- Land that was previously degraded can become productive through the implementation of half-moons.
Drawbacks
Implementing half-moons is very laborious and takes significant people power to implement.
