Soil Degradation and Climate Change Relationships: A Review
Doreen Mbabazize
Department of Crops, Horticulture, and Soils, Egerton University, Njoro, Kenya.
Christine Atugonza
Water Resources Engineering, Faculty of Engineering and Technology, Busitema University, P.O. Box, 236, Tororo, Uganda.
Sylvia Nyamaizi *
Faculty of Land and Food Systems, The University of British Columbia, Main Hall, Vancouver, BC V6T 1Z4, Canada.
*Author to whom correspondence should be addressed.
Abstract
Climate change, driven by anthropogenic greenhouse gas (GHG) emissions like carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O), is expected to worsen extreme weather events such as droughts, altered precipitation, floods, and wildfires by the century's end. These extreme weather events can exacerbate soil degradation, diminishing soil quality and productivity, with significant implications for food security globally. In this review, we describe the interconnections between climate change and soil degradation, especially those that control nutrient cycling and GHG emissions. The key climate change drivers of soil degradation are extreme precipitation patterns and elevated atmospheric temperatures, which intensify both short- and long-term effects on soil physical, chemical, and biological properties. The rise in temperatures can lead to increased soil compaction, destabilizing soil structure and reducing soil porosity. This impairs soil aeration, diminishing both macro and microbial activity, which disrupts nutrient cycling and contributes to soil degradation. Increased flooding promotes leaching and soil erosion which increases soil organic matter (SOM) and nitrogen (N) losses. This destabilizes soil N stocks and can retard proper crop growth. Frequent droughts inhibit enzymatic activities such as phosphatase responsible for phosphorus (P) mineralization, reducing the amount of phosphates available for plant uptake. Additionally, the continuous rise in temperature increases microbial activity resulting in increased SOM decomposition and release of CO2 into the atmosphere contributing to global warming. The changing precipitation patterns, especially intensive precipitation, increase anaerobic soil conditions which decrease soil microbial activity, thereby disrupting nutrient cycling. The above changes referred to as climate change-induced soil degradation in this review, alter the capability of soil properties to sustain food security and soil health necessitating the integration of adaptation and mitigation strategies to ensure sustainable functioning of terrestrial agroecosystems. Addressing this critical issue, we have identified the challenges in mitigating these impacts and proposed remediation strategies based on existing scientific knowledge.
Keywords: Adaptation, drought, elevated carbon dioxide, elevated temperatures, flooding, global warming, soil properties, wildfires