Location: Soil Dynamics Research
Project Number: 6010-11120-009-032-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Aug 15, 2024
End Date: Aug 14, 2028
Objective:
Contribute to the Inflation Reduction Act Measurement Monitoring Reporting and Verification Action Area 2-Cropland through measurement of cropland methane and nitrous oxide emissions.
Approach:
This study will be conducted for seven consecutive years to evaluate the influence of cover crops and PGPR microbial inoculants on corn growth parameters and yield under field conditions at one of Alabama Agricultural Experiment Station’s Research farms starting spring of 2024. The study will be conducted on a Coastal Plain soil (E.V. Smith Research and Extension Center, Shorter, AL), which is a common soil-type of the Southeastern U.S. This study will be evaluated using poultry litter and UAN in two separate experiments. The microbial treatments will be applied over the row at seeding and evenly to the entire plot using a spray boom approximately two weeks after emergence using a suspension concentration of 1x107 CFU mL-1. The PL will be administered to the plots evenly by hand simulating broadcast application using a litter applicator. The UAN will be administered to the plots as side-dress using a 4-row liquid nitrogen applicator. Corn silage yield will be determined by harvesting a 1.5 m section (aboveground only) from the two outside rows of each plot. Corn grain yield will be determined on the middle two rows using a corn combine. For both the inorganic and poultry litter experiments, greenhouse gas emissions from soil will be measured using in situ custom-made, vented, static gas flux chambers constructed according to GRACEnet protocols (Parkin and Venterea, 2010). Flux measurements will be taken on days 3 and 6 after microbial treatment application to the entire plots. After fertilization (3 days after PGPR application), flux measurements will be taken on days 0 (day UAN/PL application) 1, 2, 3, 6, 9, 14, and approximately weekly thereafter until harvest. Sampling frequency will be based on assumptions that most of the total direct gas emissions generally occur within the first month after fertilizer application. Gas fluxes will be calculated from the rate of change in trace gas (CO2, N2O, or CH4) concentrations within the chamber’s headspace at 0-, 20-, and 40-minute intervals during chamber closure as described by Parkin and Venterea (2010).
