A zaï pit, or planting pit, is a shallow, conical pit, generally about 1-2 feet across, in which you plant crops. This is a very common alternative to furrows used across Africa, as it takes less labor when you are preparing a field without the help of a plow and large animal, results in less water run off, and allows for targeted fertilizing.
The term zaï pit was popularized in the 1980s by Yacouba Sawadogo, a farmer from Burkina Faso who became well-known for using planting pits in an anti-desertification project. He used zaï pits with a small amount of compost and manure, finding that this not only provided fertilizer, but attracted termites that tunnel into the soil and loosen it, allowing roots and rain to penetrate into the soil more quickly and deeply.
Zaï pits, under many various names, are especially common in Africa, as the continent has many areas with poor soil, and many subsistence farmers who plant all crops by hand. In many areas the farmers work to plant as much of the land as possible, with many planting pits dug wherever possible; the term zaï pit may be used to emphasize the practice of active fertilization to support increased yields and soil health, rather than the "plant as much wherever you can" method.
Zaï is pronounced with a long i, "zie" (IPA /zī/). Other terms used include tassa, towalen, planting pockets, planting basins, and micro pits.