The Role of Integrated Nutrient Management System for Improving Crop Yield and Enhancing Soil Fertility under Small Holder Farmers in Sub-Saharan Africa: A Review Article

Fertilizer usage plays a major role in the universal need to increase food production to meet the demands of the growing world population. Fertilizer application resulted in marked crop yield increases, which for most crops were more than hundred. The extent to which fertilizers are used still differs considerably between various regions of the world. Mostly in Ethiopia Urea and DAP are the only fertilizers that are used in agricultural productivity. But using balanced fertilizers has an impact on plant growth and physicochemical properties of soil. Due to the continuous decrease in organic matter and nutrient content of the soil, the importance of integrated nutrient management for efficient utilization of nutrient resources and for long-term maintenance of soil fertility has been indicated. Therefore, the aim of this review was to review the role of integrated nutrient management for improving crop yield and enhancing soil fertility under small holder farmers in sub-Saharan Africa, especially in Ethiopia and recommend the appropriate approaches for enhancing soil fertility and increasing crop yield for small holder farmers in sub-Saharan Africa, especially in Ethiopia. So, the results of this review showed that, the integrated application of organic and inorganic fertilizers improve productivity of crops as well as the fertility status of the soil. Nevertheless, though ISFM is the notably preferred option in replenishing soil fertility and enhancing productivity, it is not yet widely taken up by farmers. The reasons for this are many, which include access or availability of inputs, use of organic resources for other purposes in place of soil fertility, nutrient balancing, collecting, transporting and management of organic inputs and economic returns of investments. These are the key challenges of adoption in the scaling up of such alternative soil fertility management practices to millions of small-scale farmers in the country. There is a need, therefore, for research and extension to sort out issues of adoption and scaling up of the available options. In order to address soil fertility problems, potential synergies can be gained by combining technical options with farmers’ knowledge as well as training of farmers and development agent on new soil fertility management approaches. Keywords: Fertilizer, integrated nutrient management, ISFM and adoptio