Understanding the impact of soil sodicity on mycorrhizal symbiosis: Some facts and gaps identified from cotton systems

Abstract Soil sodicity degrades land and more than half of the world’s sodic soils are in Australia. Farmers in Australia produce and export cotton grown in sodic soils. Undesirable physicochemical constraints (e.g. high pH, high bulk density, low porosity and reduced oxygen content) are associated with sodic soils and may adversely affect microbial interactions in the rhizosphere, including mycorrhizal associations. This viewpoint focusses on facts and gaps in our knowledge about mycorrhizal associations in sodic soils, with special attention to cotton systems. We highlight the difference between saline and sodic soil conditions and the impacts they may have on host plant-mycorrhizae symbiosis. This viewpoint identifies the need for more research on the potential impact of sodicity on mycorrhizal species diversity, functionality and benefits to crop growth. Changes in agronomic management strategies to maximize mycorrhizal symbiosis benefits are suggested, especially for those plant species, like cotton, that are highly reliant on mycorrhizal symbiosis for optimal growth and nutrient uptake.