Status of pH, Available Sulphur, Organic Carbon and Total Nitrogen on Some Small Holders’ Farms in the Sudan Savanna of Nigeria

Surface samples were collected from 6 different local governments across Kano state: Ajingi, Gezawa, Gabassawa, Gwarzo, Kabo, Tofa local government areas. The collected soil samples (0-15cm depth) were analyzed using standard procedures to determine the levels of soil pH, Organic carbon, Total nitrogen and Available sulphur in sorghum and millet based cropping systems in the Sudan savanna of Nigeria. Results obtained shows that the soils were generally low in organic carbon (0.22 – 0.51%) while the total nitrogen fell within moderate range from (0.11 – 0.12%).The pHwater ranged between 6.02 – 6.46 and pHCaCl2 between 5.55 – 6.32. The available sulphur content of different cropping systems under the study were found to be within the moderate range from (8.3 to 21.9%) with the highest mean recorded from Cowpea, Soybean and Sorghum (COS) cropping system and the lowest mean was recorded in Cowpea, Groundnut and Millet (CGS) cropping system. Owing to the low total nitrogen and organic carbon content in the soil under the study area, it is therefore recommended that supplementary nitrogen application and improvement of the drainage conditions of all the soils should be employed to improve the nutrient status of the soils. Also, with the current intensive cropping pattern, sulphur contained fertilizer should be used frequently to prevent depleting the soils which are presently adequate in sulphur within few years.