Risk mitigation strategies and policy implications for carbon dioxide (CO2) emission in organically- amended soils in Nigeria

Abstract

Global food security has been a challenge, especially in Africa. This has attracted the adoption of strategies to improve soil productivity and crop yield. One of such strategies is the use of solid wastes as soil organic matter amendments. An investigation of the effects of soil amendment using poultry manure, sawdust and their mixtures on carbon dioxide (CO₂) emission, maize (Zea mays L.) growth and dry matter yield were assessed under laboratory and greenhouse conditions. Top soil obtained from unfertilized plots at the Obafemi Awolowo University Teaching and Research farm, Ile-Ife, Nigeria was used for the experiments. The organic amendments were added at the rate of 10 g/kg, treatments were in triplicates and treatment means were separated using Duncan’s Multiple Range Test at 95% level of significance. Results obtained revealed that CO₂ emission decreased while maize heights and dry matter yields significantly (P > 0.05) increased with increasing ratios of poultry manure in the poultry manure-sawdust mixtures. The CO₂ emission from poultry manure amended soil was about 61% that from sawdust amended soil while the mean height and dry matter yield in sawdust-amended soils were 84% and 52% respectively those obtained in poultry manure amended soil. This paper concludes that it is essential to design and implement policies that will guide and encourage the use of organic amendments at ratios that can enhance crop yield and mitigate CO₂ emission to the environment.

Key words: Food security, solid waste, carbon dioxide emission, organic amendments, environment and policy.