Formulation and Evaluation of NPK Supplementary Fertiliser from Sisal (agave sisalana) and Livestock Waste Materials
Most of the Inorganic fertilizers used in Kenya like in most sub-Saharan countries are imported as a result of luck of raw materials or the costs of processing are not realistic. Since not locally produced the cost of these farm inputs are therefore high and inaccessible to the majority of the smallholder farmers as the prices are dictated by international market forces. A sustainable home based mechanism to supplement the imports is therefore necessary. The agricultural activities in Kenya (on small or large scale) have included among others growing sisal, maize, sugar cane and livestock keeping. These activities generate enormous wastes that are underutilized and yet are rich in plant macronutrients of nitrogen, phosphorous and potassium (NPK). This study sets out to investigate how wastes generated can be used to formulate an NPK supplementary fertilizer. It will involve laboratory formulation, evaluation and fieldwork to test its effectiveness compared to the commercial fertilizer. The laboratory analysis will establish the levels of macronutrients with wet digestion of the samples followed by standard elemental analysis methods: Kjeldahls method for nitrogen, ascorbic acid method for phosphorous and AES for potassium. The data generated will be analyzed by SPSS version 20 to establish the mean levels of the macronutrients in both raw materials and the product, calculate correlation coefficients of NPK elements with the materials used for bulking. A t-test to compare the yields using the formulation and the commercial fertilizers will also be done. It is hoped that the study will formulate a cheap and effective supplementary (NPK) fertilizer. It is also expected that by utilizing the wastes, we shall not only diversify their uses but also reduce the environmental dump sites and pollution.