Macro and Micro-Nutrient Status of Selected Kenya Soils

Abstract

Over the years there has been a decline in soil fertility in Kenya, which is responsible for low crop yields. Macro and micronutrients should be added to the soil as they ensure healthy produce by supplying the right balance of nutrients to the soil. Most farmers rely on nutrient recycling in their farms which is not sustainable as it leaves the soils depleted of nutrients. A study was therefore conducted to assess the limiting nutrients of soils in Coastal, Eastern, Rift Valley and Western parts of Kenya. Twenty-three soil samples (0 to 30 cm) from 13 counties were collected and evaluated for total nitrogen, total organic carbon, phosphorus, potassium, calcium, magnesium, manganese, copper, iron, zinc, sodium, electrical conductivity, cation exchange capacity (CEC), base saturation and soil pH. The mean values were 0.12%, 1.12, 19.09, 220.43, 1397.39, 163.98, 120, 52, 3.95, 52.78, 1.86, 92.80 mg/kg, 0.11mS/c, 11.98 Cmol (+)/kg, 83.13% and, 5.96, respectively. The soil analysis results indicated that nitrogen, phosphorous and zinc were deficient in most soils in Kenya. Nitrogen and carbon were positively correlated with each other (P≤ 0.01). Phosphorous on the other hand was negatively correlated with carbon and nitrogen. Zinc was negatively correlated with soil pH. The exchangeable bases showed significant correlation with each other. It was evident that the inadequate nutrients need to be considered and supplied for restoration of soil fertility and productivity.