This study characterized and classified soils along a toposequence and its implications on agricultural activities in Dundaye district of Sokoto State, Nigeria. Two pedons on three (3) different topographical positions (summit, shoulder and foot slope) on a toposequence were studied. The Summit was on relatively flatland with an elevation of 283m above sea level; shoulder was a gently sloppy land with an elevation of 271m above sea level, while the foot slope was on a low land with an elevation of 262m above sea level. Morphological properties of the soils revealed that soils of the upper slope were shallow and perfectly drained and were generally sandy in texture. Those on shoulder were deep and well drained while those at the foot slope have subangular blocky structure with evidence of biological activities at the surface. Physical properties of the soils indicate a relatively high bulk density and high porosity. The dominant exchangeable bases were Ca and Na. The soils were slightly acidic in reaction with pH range of 5.3 to 5.4, 5.2 to 5.4 and 6.5 to 6.7. Organic matter content of the soils was generally low range from 0.33 to 0.37, 0.08 to 0.16 and 0.88 to 0.93. The soils were rated low in nitrogen. The results of available phosphorus show an irregular distribution in the profiles. The soils were rated having very low available phosphorus. The implication of these on crop production is that: the pH value was rated slightly acidic to neutral which favours the cultivation of grain crops. The low organic matter content recorded on most of the soils cannot sustain crop production on long time bases. Therefore, the study recommend that the organic matter content must be substantially increased through effective crop residue management; use of mineral and organic fertilizer; addition of more organic manure and crop residue for optimum plant growth.
Keywords: classification; crops production; catena; soils, toposequence
