An Agronomic Approach for Carbon Capture and Utilization of Carbon Dioxide Emissions.

Climate change, air quality, water scarcity, and energy security are important political, environmental, and agricultural issues in California (CA), the United States of America (USA) and the rest of the world.  Global warming is linked to increases in anthropogenic greenhouse gas concentrations, largely carbon dioxide (CO₂).  The transportation sector, power/cement plants, ethanol production facilities and oil refineries are major sources of CO₂ emissions.  These CO₂ emissions are usually vented directly into the atmosphere if not captured and sequestered or used for beneficial purposes. Although CO₂ has different industrial applications such as carbonation, food preservation and packaging), commercial uses of CO₂ are relatively small compared to the CO₂ emissions produced.  A novel use of these emissions could be found in the agricultural sector since CO₂ is the primary component of photosynthesis and therefore plant growth.  In this presentation, we review the methodology and proof of concept involved in the design and set up of open field experiments aimed at delivering CO₂ cost-effectively for utilization by a tomato crop grown in the Central San Joaquin Valley (SJV), in CA, USA. Sixteen open-top chambers, consisting of PVC frames (15 ft W x 15 ft L x 10 ft H) with 6 mil thick greenhouse film walls were installed in a tomato field. The CO₂ was distributed throughout to the chambers from a 16,000-lb capacity CO₂ storage tank, via manifold made up of a 2-inch PVC pipeline with 0.5-inch polyethylene tube connected to 5-inch perforated PVC pipes. BH001-3S Hawk^® air mover blowers were installed in each chamber to maintain similar air temperatures inside and outside the chamber. Ambient air was circulated daily from 8 AM to 4 PM through PVC pipes. The CO₂ delivery tubing was also connected to the 5-inch perforated PVC pipes to ensure that CO₂ was equally distributed inside the enriched plots. Actual CO₂ concentrations in the chambers were monitored every 10 seconds using infrared Li-COR^® gas analyzers, as well as temperature and CO₂ sensors installed at the canopy level. Pre-fabricated gas manifolds with solenoid valves and Omega^® rotameters were used to control the flow of CO₂ delivered. Our findings to date clearly demonstrate that the system design, along with the monitoring and feedback mechanisms can effectively deliver and enhance CO­₂ capture and utilization within the crop canopy of tomatoes grown in the central SJV, CA.