SMARTFARM initiative includes developing monitoring technologies to quantify GHG emissions due to biofuel feedstock production and carbon management.
Nitrous oxide has been tagged the most significant ozone-destroying compound of the 21st Century, and agriculture is the largest emitter, accounting for 74% of emissions.
“We have to pay nitrous oxide more attention,” says Nithya Rajan, associate professor, Department of Soil and Crop Sciences, Texas A&M University, College Station.
Rajan, speaking at the recent Texas Plant Protection Association annual conference in Bryan, said Texas AgriLife research projects seek better methods of measuring greenhouse gas emissions and better farming practices to reduce those emissions.
“Carbon farming is gaining significant momentum in the U.S. and other countries as a major strategy for achieving carbon neutrality or ‘net zero’ emissions,” she said.
To take advantage of that potential market, producers and industry need to develop accurate means to measure greenhouse gas emissions and revise cropping systems to capture carbon.
“Accurately measuring greenhouse gas emissions requires high-frequency emission monitoring and state-of-the-art research instrumentation to generate necessary data,” Rajan said.
“The current U.S. Federal Government is keen to establish a ‘carbon bank;’ however, we lack a mechanism to document the actual emission reductions from agricultural fields implementing carbon farming practices.
Time and space
“It is important to account for temporal and spatial detail for all major greenhouse gas fluxes (carbon dioxide, nitrous oxide, and methane) to properly estimate carbon offsets,” she said.
She explained that an ongoing project funded by the Department of Energy’s Systems for Monitoring and Analytics for Renewable Transportation Fuels from Agricultural Resources and Management (SMARTFARM) initiative, AgriLife researchers are collecting continuous GHG emission data from a 90-acre no-till sorghum field in the Texas High Plains.
Research goals
Objectives of the research include developing monitoring technologies to quantify GHG emissions due to biofuel feedstock production and to enable new market incentives for efficient feedstock production and carbon management. The project also will determine carbon intensity (CI) associated with sorghum production and will measure greenhouse gas emissions of carbon dioxide, nitrous oxide, and methane (CO2, N2O and CH4) from grain sorghum in the Southern Great Plains.
Identifying practices to reduce nitrification and nitrogen loss as nitrous oxide are part of the project’s objective. Rajan said potential remedies include use of synthetic nitrification inhibitors such as Nitrapyrin, dicyandiamide (DCD), and 3,4-dimethylpyrazole phosphate (DMPP).
Limitations, Rajan said, are that these products are expensive, the effect may last only for a few days, and they may contaminate ground and surface waters.
The SMARTFARM project is also examining the advantages of sorghum for ethanol production. Sorghum is primarily dryland, much more drought tolerant than corn, and produces the same ethanol yield per bushel (2.5 to 3 gallons).
Sorghum is also a limited input crop and averages about 70 to 80 bushels per acre.
Carbon sink
Research from the SMARTFARM research indicated that a sorghum-no till field was a net carbon sink. Also, N2O emissions were significantly low (no fertilizer was applied), and the net carbon uptake was 4,200 kilograms per hectare.
“We are also looking for ‘climate smart’ sorghum,” Rajan said. Project goals include new sorghum hybrids with improved yield, better GHG mitigation, and improved water quality.
Early research indicates potential from wild sorghum genotypes that showed the greatest nitrification inhibition effect. “Cultivars show wide variations,” she said.
The overriding goals of the SMARTFARM project include reducing emissions or removing carbon from the atmosphere. “We need to reduce GHG emissions, especially N2O,” she said. “An increase in N2O emission will substantially increase carbon intensity,” Rajan said.
“Climate-smart farming strategies have the potential to decrease carbon intensity and increase opportunities for market incentives.”
