Harouna Sana | February 29, 2024
News Brief
In Pougyango, Burkina Faso, vast areas of degraded and bare soil stretch as far as the eye can see. Here farmers are using zai pit techniques to revitalize the degraded soils. Tasséré Kinda says he has significantly increased his sorghum, maize, and rice yields thanks to manual zai pit techniques. He digs pits about 10-15 centimetres deep and 20-40 centimetres wide during the dry season. These pits help water infiltrate into the soil. Mr. Kinda pairs this with other practices like using composted manure as fertilizer, stone lines, and mulching to bolster soil fertility. Other farmers are using mechanized zai to restore larger areas of land, although with higher costs.
Fifteen kilometres east of Yako, Burkina Faso, vast areas of degraded and bare soil stretch as far as the eye can see. The eroded soil and lack of vegetation is stark evidence of the impact of climate change. This is the village of Pougyango in northern Burkina Faso, where the main occupations are agriculture and keeping livestock.
Local farmer Tasséré Kinda grows crops on three hectares. He says the soils had become sterile, but, “Thanks to zai pits, I produce sorghum, maize, and rice. Since adopting this technique, my field yields have improved.”
Zai pits are an ancient technique to restore degraded soils from northern Burkina Faso that has been improved and popularized by agricultural researchers. It involves digging planting pits in dry, degraded soil to help water infiltrate into the soil. This enriches the soil and encourages vegetation to regenerate.
Mr. Kinda has practiced zai for about 15 years. He hand digs pits about 10-15 centimetres deep and 20-40 centimetres wide during the dry season, then places the soil he removes from the pit downslope of the pit to block runoff water. Then, he adds about 300 grams of manure or compost to the holes and lightly covers it with fine soil. At the first rains, Mr. Kinda sows seeds in the zai pits.
Mr. Kinda says that using zai helped boost his rice yield to 500 kilograms on a quarter of an acre. He says, “Without zai, we would have migrated to more humid regions.”
Mr. Kinda adds organic manure such as poultry droppings, excrement from grazing animals, and compost made from straw and crop residues to the zai pits. He also built stone lines to slow down water erosion on his farm, especially important on steeper slopes, explaining, “These lines slow the flow of rainwater, retaining humus and water for the plants.”
Amidou Kouda also uses the zai technique. But he uses a mechanized version, where an animal-drawn plough makes furrows across the slope, and other furrows up and down the slope, digging zai pits at the intersections of the furrows. Mr. Kouda has grown sorghum in Tibili, about 10 kilometres from Pougyango, for about 15 years. He farms a quarter of a hectare for his family.
The pits and the furrows that run up and down Mr. Kouda’s sloping field are spaced between 70 cm and 80 cm apart, depending on the crop. Like Mr. Kinda, when the slope is steep, Mr. Kouda uses stone lines to regulate the downward flow of water and reduce soil erosion. Mr. Kouda says that, by using zai pits, he has recovered 10 hectares of abandoned land.
Seydou Sawadogo is an agricultural engineer at the Ministry of Agriculture who has researched zai in northern Burkina Faso. He says the technique is effective for reclaiming degraded soils, especially when combined with water and soil conservation practices like grass strips, mulching, live hedges, and farmer-managed natural regeneration, many of which Mr. Kinda is practicing.
Mr. Sawadogo explains that the mechanized zai technique requires less effort from farmers and enables them to use zai pits on larger areas of degraded land. He estimates that the manual zai technique requires at least 300 hours of labour per hectare, compared to 40 hours per hectare for mechanized zai. He adds that mechanized zai promotes better infiltration and retention of water in the soil than manual zai, because the plow better breaks up the soil’s surface layer.
However, he says that mechanized zai can be costly because it requires having an animal-drawn plow and a draft animal. This can cost up to 250,000 CFA francs, about $415 US.
Mr. Kinda, who practices manual zai, says the bigger yields convinced him that zai pits are the ideal solution for reclaiming his degraded lands. He concludes, “This technique must be taught to all farmers to reclaim the land and increase production.”
This resource was produced with a grant from the Ministry of Foreign Affairs of the Netherlands and IDRC of Canada. The views expressed do not necessarily represent those of the Ministry of Foreign Affairs of the Netherlands, nor those of IDRC or its Board of Governors.
Photo: Access Agriculture Zaï planting pits, 2017