Influence of NPK Blended Fertiliser on Soil Chemical Properties under Acidic Conditions of Western Kenya on Finger Millet Crop

Soil acidity is a serious problem that affects crop productivity in Western Kenya region. The county governments of Kakamega, Bungoma, Vihiga, Busia and Trans-Nzoia are promoting the application of NPK blended fertilizer to enhance the soil acidity. Finger millet (Eleusine coracana L. (Gaertn) is one of the principal cereal crops in Kenya and can grow in stress conditions much better than other cereal crops, and it is for this reason that it is currently being popularized in efforts to address food security. NPK blended fertilizer, Commonly known as ‘Mavuno Fertilizer’ to locals contains the combination of macronutrients and micronutrients (10%N, 26%P2O5, 10%K2O, 4%S, 8%CaO, 4%MgO and traces of B, Zn, Mo, Cu and Mn) that makes it unique to ameliorate this acidic soil conditions. The study was conducted at the crop and livestock research field at Kenya Agricultural and Livestock Research Organization (KALRO) Kakamega station. The design was Randomized Complete Block Design, with 0,25,50,75,100 kg application rates per acre of NPK blended fertilizer as the treatments applied in two equal split application. The application of NPK mixed fertilizer reduced the amount of aluminium in the soil consistently for both seasons with the highest reduction under the highest rate while the soil pH, soil calcium and soil magnesium significantly increased linearly with increasing fertilizer rates. The control had no significant influence on the soil pH compared to the treated plots as compared to the analytical results of the soil pH of 5.71-5.73 before planting. The soil aluminium content drastically reduced from 2.10 cmol/kg in control to 1.4 cmol/kg in the 100 kg/acre in both rain seasons under the local variety Gulu-E with slight differences from P-224. The highest application rate of 100 kg/acre significantly increased the soil calcium contents to 3.4% and 3.3% during the short and long rainy seasons respectively. The NPK blended fertilizer application from any rate can positively ameliorate the soils in western Kenya by reducing the acidity.