Conceptual framework for restoring soil fertility in arid Borno state, Nigeria with biochar from agricultural wastes

Borno State situated in Northeastern Nigeria, has an arid agroecosystem that is defined by severe climatic problems such as droughts, desertification and irregular rainfall and poor soil fertility. The burning of crop residues results into depletion of soil organic carbon and essential plant nutrients. A sustainable approach is producing biochar from locally available agricultural wastes. This review presents locally available agricultural wastes as sustainable feedstock for biochar production and their potential to improve soil health in the arid and semi-arid region of Borno State. To achieve this, related articles were sourced from Google Search Engine (possible criteria to obtain local articles for Borno State), Google Scholar, Scopus with key words like “Borno, arid and semi-arid, biochar, agricultural waste” and related articles were selected from the search results. Notable available feedstocks obtained from the result include groundnut shells, sorghum stalks, rice husks, maize cobs, and an invasive plant specie known as ‘Prosopis juliflora’. Based on conceptual framework, utilizing reports from other arid regions, biochar from these feedstocks positively improved soil conditions of the arid regions and outperformed direct organic waste utilization for long-term plant nutrition benefits. For example, in an arid environment, sorghum waste and wheat straw biochar increased winter wheat yield and rice grain by 31 and 49% respectively. Implementation of biochar technology as part of the post-conflict plans, can benefit farmers when adopted as it accomplishes the objective of soil restoration through waste-to-value transformation. Although, the limitation of this study lies in the absence of empirical evidence due to non-availability of data specific to Borno State.However, successful implementation of this sustainable arid soil management practice in Borno State depends on research alongside localized production systems together with policy support to overcome economic obstacles like production expenses and technical limitations.