Baseline Soil Information For Rangeland Management

No Thumbnail Available
Journal Title
Journal ISSN
Volume Title
Ministry Of Agriculture
The paper outlines the major types and forms of soil information that are necessary prior to articulation of rangelands for increased production and/or amelioration of their ecological conditions. In Kenya, the rangelands cover 50 million hectares out of which 96% are semi-arid. Fourteen major soil types were found to be common within these rangelands, mostly of volcanic and metarmophic in origin. A case study; the Kiboko Range Research Station; located in a semi-arid environment was selected. The soils were surveyed at a semi-detailed level of intensity (scale 1:50,000) specifically to avail information that could assist objective range experiments. Nine orders of soils are described viz: Ferralsols, Nitosols, Luvisols, Cambisols, Vertisols, Chernozems, Solonchaks, Regosols and Lithosols. Physical, chemical and fertility aspects of the soils were discussed. In the case study, adequate soil information is availed indicating effective soil depth, soil moisture, oxygen availability, nutrient status and occurance of alkalinity, salinity and sodicity. However data on infiltration, erosion (types and intensity) and runoff are scanty. The effect of soil properties on rangeland management decisions through their influence on pasture performance and hence rangeland productivity were examined. They include the inherent physical and chemical properties of the soil; the occurence of adverse chemical substances such as salinity, sodicity and alkalinity that can impair pasture performance and the capability to maintain the soil fertility for a period of time. It was observed that both physical and chemical soil properties and the presence of adverse chemical conditions (alkalinity, salinity and sodicty prevalent in semi-arid environments) affected pasture perfomance. It was also noted that soil information must be as detailed as possible but at the same time digested for easier application by the rangeland manager. There must also be a complete assessment for all factors including infiltration, erosion and runoff for all soils in a given area. Also information on pasture requirements as reguards soils appears to be very scanty indeed.