ROBOTIC GREENHOUSE GAS MONITORING TO MEASURE IMPACTS OF CLIMATE-SMART FARMING PRACTICES

Major Goal of Project: Develop and test a low-cost, automated system (FluxBot) for measuring fluxes of greenhouse gases (GHGs) on crop fields.Technical Objective 1: Redesign Autosampler. The novel design of the FluxBot leverages an autosampling system contained within a rigid chamber installed over a patch of soil in a crop field. Prior to the start of the project, a V2 design of the autosampler (syringe pump) system will be completed and tested. Over the first two months of the project, a final V3 design will be completed based on testing of V2. The final design will be used in Technical Objective 5.Technical Objective 2: Redesign Chamber Movement. It is necessary for the FluxBot chamber to be periodically opened such that the soil surface can be exposed to the atmosphere. This opening and subsequent closing for sampling needs to be automated and carried out such that interference from the crop does not occur. A V2 concept for chamber movement will be developed prior to the start of the project and a V3 concept will be developed and tested over the first two months of the project. The final design will be used in Technical Objective 5.Technical Objective 3: Redesign Chamber Base. Conventional chambers rely on bases that are installed semi-permanently in the soil and on which the chamber seals. The bases need to be lighter weight than the V1 design while also providing rigidity and a flat mating surface for the chamber. A V2 design will be completed prior to the start of the project and a V3 design will be refined and tested during the first two months of the project. The final design will be used in Technical Objective 5.Technical Objective 4: Redesign Chamber. The V1 chamber proved to be unnecessarily tall, which led to a large inside chamber volume. This may create stratification of trace gasses inside the chamber; it also makes for a cumbersome chamber to move. Pending advancement of Technical Objective 1, a new chamber (V2) will be designed prior to the start of the project and refined (V3) during the first two months of the project. The redesign will include attention to the packaging of electronics in a manner that is durable and capable of withstanding exposure to moisture. The final design will be used in Technical Objective 5.Technical Objective 5: Produce Updated Full System. Over the first two months of the project five V3 complete systems will be produced, with preliminary "shake out" testing extending into the third month. There will be ongoing software improvements made over the course of the first six months of the project. As shortcomings of the V3 design are revealed, a V4 design will be completed primarily during months three and four in preparation for a Phase II project.Technical Objective 6: Develop Automation Features. There are several features that will facilitate deployments of the FluxBot system in the future. It is necessary to estimate the volume of air contained within the bases that are semi-permanently installed in the soil. Over the first four months of the project methods for estimating this volume using smartphone images will be tested. Longer-term deployments would benefit from solar charging of the FluxBot's onboard battery, and sizing of such a system will be carried out during months four to seven in parallel with the V4 design for Phase II.Technical Objective 7: Test FluxBot v. Conventional Chambers. Testing and evaluation of the FluxBot automated chamber compared to conventional chambers will be performed weekly on a test field at the Rosemount Research and Outreach Center (RROC) that is part of the University of Minnesota. The test field will be prepared with low, medium, and high nitrogen fertilizer application zones during months one and two of the project. Testing is expected to be conducted twice weekly over months three to seven.Technical Objective 8: Evaluate Impact of Circulation in Chamber. Depending on the volume of the final V3 chamber resulting from Technical Objective 4, there may be a benefit to using a fan to gently mix air in the chamber prior to sampling events. Testing over months one and two will be carried out so that circulation, if necessary, can be implemented for most of the testing described in Technical Objective 7.Technical Objective 9: Test FluxBot Movement Automation. Apart from testing the automated chamber function compared to conventional chambers (Technical Objective 7), testing of the automated opening and closing design (Technical Objective 2) will be carried out during months three through five. This testing will inform the V4 design (Technical Objective 5) for a Phase II project.Technical Objective 10: Test FluxBot 24-hr Sample Collection. A virtue of the FluxBot design is that fully-automated sampling can be carried out over extended periods of time. During months three through five, side-by-side testing will be carried out comparing a FluxBot that is manually opened and closed to one that has automated movement (opening and closing).