Motivation
Sustainability
The challenges of increasing productivity and sustainability in agriculture are considerable. Atmospheric carbon concentrations are at unprecedented levels in recorded history. Current food production rates will be outpaced by demand by the year 2050. With drought frequency and extreme weather events increasing, growing food reliably will be made even more difficult. Curbing emissions and increasing carbon sinks is key to meeting our goals for a sustainable future.
Climate Change Mitigation
SUBTERRA seeks to identify corn root traits that will enable plants to harness atmospheric carbon and sequester it at depth in agricultural soils. Differences between maize genotypes in root structure and composition allow roots to contribute different amounts of carbon to the soil. Geneticists can take advantage of this variation to discover and breed varieties that have a high rate of carbon sequestration. In tandem with our discoveries of root traits that help to sequester carbon, we will discover traits contributing to drought tolerance and improved soil health.
Plants take in carbon dioxide during photosynthesis, using the carbon and oxygen to make sugars and respiring the remaining oxygen. Plant tissues and exudates are composed of carbon which, when incorporated into soil, can be stored for long periods of time. Agricultural practices as well as crop varieties can be optimized to leverage this natural process so that crop lands can again be a significant sink for carbon.
Potential Impacts
Economic
Loss of organic carbon correlates with high economic cost. $44 billion per year is lost from erosion of soil organic carbon from agricultural production. Preserving carbon stored as organic matter is a viable, efficient, and valuable approach to reduce economic expenditure.
Corn is grown on close to 90 million acres of American cropland annually. The magnitude of this industry makes corn a scalable and appealing venue for optimizing carbon sequestration in agricultural systems. With appropriate incentives for farmers to increase carbon sequestration in their soils, this strategy to taking on atmospheric carbon has great potential. Farmers who adopt incentivized practices to increase their soil organic carbon will also experience the benefits of improved soil health.
Environmental
Identifying genes that control improved root-soil function could dramatically reduce atmospheric CO2 concentrations without adversely affecting agricultural yields. SUBTERRA aims to develop favorable genotypes that demonstrate a 50% increase in soil deposition depth and accumulation, a 50% decrease in fertilizer N20 emissions, and a 25% increase in water productivity.
Security
Strategic agricultural production is critical to national food and energy security. Improving crop characteristics will enable increased production of maize for food, feedstock, and fuel.
Illustrated above is some of the root structure variation that we find in a diverse population of maize. By studying individuals along this spectrum of variation, we can discover causal genetic variants and use them to target selection for traits of interest.