J.N. Barasa, E.N.Omami, J.R.Okalebo & C.O.Othieno
Soil acidity and low phosphorus status are the key factors underlying low crop production in Uasin Gishu District. An on farm experiment was conducted during the 2007 and 2008 cropping season to test the effects of agricultural lime (20.8% CaO) and Triple superphosphate (TSP) (12-14% CaO) on some soil properties and two French bean varieties namely: Samantha and Amy. The bean varieties grown in acid soils (pH 5.0) at Kuinet, Uasin Gishu District received 0 and 2 t ha-1 lime and 0, 20 and 40 kg P ha-1 (TSP) and their combinations. Lime significantly increased soil pH from 5.5 to 6.3 and 5.4 to 6.0 for the first and second seasons, respectively at the end of the study period. P alone had no significant effect on soil pH, but increased soil available P between 8.7 and 14.7g/kg-1-. Positive responses of the two crop varieties were observed. This gave GM of Kshs 84,200 and 44,200 respectively. The effects of lime and TSP (With Cao component) were attributed to a favorable positive change in soil pH which increased the availability of soil nutrients through organic matter decomposition or direct release from TSP and availability to the crop and subsequent uptake of the nutrients by the crop. Economic analysis of the crop yields reflected higher returns from both lime and P, particularly in the pods harvested seven weeks after planting. The study demonstrated the superiority of Samantha French bean variety over Amy despite being the most popular within the region. The need for complementary lime and phosphorus application is recommended for acid soil fertility improvement and high crop yields.
Published Date: 2013-05-13;