Relationships between soil Physico-chemical properties and bacteria counts in Nzoia Sugar Company farms, Kenya.

catherine wanjiru kariuki


Bacterial communities largely influence decomposition, nutrient mineralization and nutrient cycling and thus contribute to soil and vegetation patterns. Subsurface bacterial communities may sequester nutrient limited plants. Although studies on examining the factors that influence the soil microbial communities in various ecosystems are substantial, the factors driving this biotic community in the Nzoia Sugar company farms have not been studied. In this study, the importance of soil physico-chemical properties in driving soil bacterial communities in the Nzoia sugar company farms in Kenya was examined. Soils were collected from five Sugarcane farms of Nzoia Sugar Company. Results show a large range of variation in the total bacterial colony counts (6.1 x 105 to 18.7 x 105 cfu-1g of soil). Soil moisture ranged between 16% and 21%; pH 4.6 to 5.5 and soil temperatures were between 16oC and 28oC.  Data of the present study revealed that number of total viable bacterial count was significantly and positively correlated to pH, with r = 0.549, indicating that pH was a major driving factor of bacterial communities in Sugarcane farms of Nzoia Sugar Company. Results also showed significant differences in viable bacterial counts among the farms. Such differences in the bacterial population size between these farms might be related to change in soil properties due to human activities mainly agricultural practices.

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