IMPACT OF LIMING ON BIODIVERSITY IN ACID SOIL FALLOW FARMLAND IN KAVUTIRI, EMBU COUNTY

Abstract

midland zone 1 (UM1) also referred to as tea zone. Kavutiri area in Embu County is composed of mainly small-scale farmers. Small-scale farmers often leave their land fallow when they became very unproductive. Kavutiri soils have overtime developed high acidity levels ranging between pH 4.2 and pH 4.6. Soil acidification disrupts biodiversity due to saturation and consequent toxicity of elements such as aluminum and manganese and unavailability of nutrients such as phosphorus, magnesium and calcium. Proper liming ameliorates soils by replenishing soil base cations and reducing soil acidity. However, the response of biodiversity to liming in Kavutiri was not known. There was therefore a need to investigate the impact of liming on biodiversity. This was done by characterizing the physical and chemical changes of acidic soil resulting from liming, established the frequencies of flora and fauna species resulting from soil liming and finally determining the relationship between soil liming and biodiversity in acid soil. The site was identified within an area previously left fallow for two seasons in Kavutiri area, Embu County. Vegetation and debris on the land area measuring 32 m x 28 m were cleared. A randomized complete block design with four blocks and four treatments per block was laid out. The treatments comprised rates of lime which were as follows; 0 (L0), 2.4t/ha (L1), 6t/ha (L2) and 8t/ha (L3). The lime was applied mixed into 0-15 cm depth of soil. . Since lime react very slowly (Smith et al., 1994), five months reaction period was allowed. The plots were weeded in the 5th and 11th