Enhancing plant growth and carbon harvesting for sustainable agriculture

Abstract

Society is in dire need of solutions to address complicated threats like climate change. To do this will require redesigning many of our current infrastructure and processes. Agricultural systems are one essential part of supporting society that could be made more sustainable. If efficiency is increased and plant growth enhanced, this would also contribute to balancing carbon dioxide (CO2) fluxes by increasing carbon harvesting, which can help address climate change. The impact of environmental parameters affected by climate change was incorporated through a manipulative greenhouse study to understand the impact of the increased intensity of precipitation on spinach yield and crop quality. Excess water treatments consistently increased levels of secondary chemicals. Impacts of the higher intensity storm treatment were seen in limited growth and a stress response in the roots. This could inform management of crops for nutritional quality. To enhance growth and optimize efficiency of crop production in new agricultural spaces like rooftop gardens and farms, a system was developed to apply indoor air with high CO¬2 concentrations from human respiration to rooftop crops through exhaust vents. The CO2 resource was first characterized finding levels averaging above 1000 ppm in classrooms during the daytime throughout the week and above 800 ppm from exhaust vents. Growth of spinach and corn besides vents increased by 2 to 4 fold indicating the effect of other characteristics besides CO2 concentration as contributing to growth effects. These systems could increase efficiency and success of rooftop gardens and farms. Decreasing fertilizer usage through use of a more sustainable plant enhancer would decrease impacts on surrounding environments, while still enhancing production. A lithotrophic gas fermentation system was used to grow a hydrogen-utilizing bacterium, Cupriavidus necator, which was engineered to produce lipochitin oligosaccharides (LCOs), a plant growth enhancer. LCO production was confirmed and the product was applied to relevant crops and a growth enhancement was attained. By understanding and increasing crop growth in creative ways, this study provides options for developing a more sustainable agricultural system, which works synergistically with nature and assists in increasing carbon harvesting and finding a sustainable path for society