VARIATIONS TEXTURALES ET CHIMIQUES AUTOUR DES TOUFFES D’Hyphaene thebaica (MART) DES SOLS DANS LA REGION DE MARADI (NIGER)

Abstract

Maradi region is one of the agricultural areas of the Niger, where the anthropogenic pressure on land is very high, resulting in their depletion generalized. In the Goulbi N kaba, particularly in the region of El Gueza, farmers have adopted agroforestry in the cropping system to cope with the declining fertility of the soil, and the loss of vegetation cover. Thus, Hyphaene thebaica, very prevalent in this region, is one of the species in agroforestry systems that these farmers have integrated it into their system of farming, given its socio-economic and ecological potential. The present study focuses on the influence of Hyphaene thebaica tufts on the soils fertility in the land of El Gueza. Thus, a device in blocks randomized complete with three repetitions of the tufts, has been used. Samples of the soil have been carried out around the tufts according to the cardinal points, the distances of 0, 50, 100, 150 and 200 cm of the tufts and the soil depth (0 -10 ; 10 -20, 20 -30 and 30 -40 cm). It is clear from this study that the soil fertility in the presence of the tuft of Hyphaene thebaica is significantly improved. In effect, the organic matter content, exchangeable bases, phosphorus, as well as the pH and CEC decreases significantly as one moves away from the tufts. These levels are significantly greater in the East and West sides, the main directions of the harmattan and monsoon, as in the North and South sides of the tuft. This significant improvement of the physico-chemical parameters of soils in the presence of Hyphaene thebaica is mainly due to the role of this species in the enrichment of soil organic matter and mineral elements through the litter of his palms and the trapping of the particles carried by the wind.