In this arid zone, water is capital for increasing yields, justified why zaï, which is characterized by spherical pits, has been become the main soil recovery technique. However, water runs by table, this zaï would be limited by its ability to collect sufficient water. The present study consisted in giving a rectangular shape to the usually spherical zaï pits to measure the straw and grain yield of the sorghum in a factorial design: lengths of pits (30-35-40 and 45 cm) of a constant depth of 20 cm, type of amendments (Compost, NPK, compost + NPK and no input) with 4 repetitions. At Sahelian zone and Sudano-Sahelian zone, straw mass and grain yield were assessed. The results showed that the rectangular zaï produced significantly better straw (4941 kg/ha in 2019 and 2490 kg/ha in 2020) and grain (844 kg/ha in 2019; 839 kg/ha in 2020) yields than the ordinary zaï (3609 kg/ha in 2019 ; 1596 kg/ha in 2020 for straw and 588 kg/ha in 2019 and 460 kg/ha in 2020). The application of compost combined with NPK under rectangular zaï in 45 cm long pits significantly increased grain yield much more in the Sahelian zone (1890.5 kg/ha in 2019; 2269.0 kg/ha in 2020) than in the Sudano-Sahelian zone (1750.0 kg/ha in 2019; 1634.6 kg/ha in 2020), with a downward trend over time. The good runoff collection capacity and the combination of compost and NPK would have created a better water and nutrition condition, reflected in this yield. Rectangular zaï was therefore the best technique compared with ordinary zaï, and requires high-quality organo-chemical matter, mainly in the Sahelian zone.

Keywords: Land degraded, soil fertility, rectangular zaï, sorghum