Dear Chief Cosby::
The undersigned coalition of conservation and agricultural groups submits the following comments in response to NRCS’ Climate Office solicitation for comment on its Climate-Smart Agriculture and Forestry Mitigation Activities List (CSAF List) for FY 2025. This submittal further responds to NRCS’ specific request for relevant scientific literature supporting the climate change mitigation benefits of specific activities.
We appreciate NRCS’ addition of irrigation practices 430 (irrigation pipeline), 441 (microirrigation), 442 (sprinkler system), and 533 (pumping plant) to the list of climate-smart mitigation activities eligible for funding under the Inflation Reduction Act (IRA) in FY 2024. We strongly encourage NRCS to keep those practices on the CSAF List for FY 2025, and to remove the “used to reduce energy use” qualifier associated with those practices. This limitation is unduly restrictive because it suggests that the only climate smart benefit associated with implementing irrigation practices is the result of reductions in energy use. The body of science says otherwise, and we encourage NRCS to follow that science.
As detailed in the technical compendium assembled by The Freshwater Trust (attached as Appendix A, and published in The Water Report), where an irrigation practice change makes sense for producers,[1] impactful climate smart benefits beyond reductions in energy use are produced. Specifically, a growing body of peer-reviewed studies demonstrate that converting gravity systems to pressurized pipe systems quantifiably reduces nitrous oxide (N2O) and methane (CH4) emissions [2]—both of which are climate smart greenhouse gas (GHG) parameters under the IRA. In short, these studies find that flood irrigation results in greater losses to seepage below the root zone compared to pressurized sprinkler and microirrigation/drip systems. Pressurized, more frequent, and targeted irrigation systems reduce GHG emissions through more consistent and direct watering of crop roots. This approach moderates the two major processes that drive GHG emissions in unpressurized systems: (1) soil wetting and drying cycles that increase N2O emissions and (2) soil anoxic conditions that increase methane emissions. Pressurized irrigation systems also improve uptake of nitrogen by plants (further reducing N2O) and decrease nitrogen runoff and leaching that cause indirect N2O emissions.
As further evidence of these benefits, TFT has applied NRCS-approved quantification methodologies (Nutrient Tracking Tool, COMET) to thousands of agricultural fields and consistently found that these models show quantifiable GHG reductions.
In addition to delivering climate smart benefits, irrigation upgrades improve water quality, and offer more precise water management options that can create more water system flexibility, drought resilience, and economic options for producers. As outlined in NRCS’ Western Water and Working Lands Framework, it will be critical to protect surface water availability and sustain agricultural productivity in the face of unprecedented water scarcity challenges driven by climate change. Irrigation practices offer producers a critical tool in managing this uncertainty.
On a practical level, where supported by robust science, we encourage NRCS to publish a broader CSAF List, not a narrower one. All IRA funds must be obligated by 2026 and spent by 2031. This creates intense pressure to get money to projects right now even if additional scientific analysis could be useful. Paired with the IRA funding USDA secured to improve GHG quantification approaches, investment in and study of a more expansive list of practices will improve overall scientific rigor, and undoubtedly discover new things.
We believe that these factors overwhelmingly support an expanded role for irrigation practices on the CSAF List moving forward. We therefore recommend that NRCS: (1) keep these essential irrigation practices on the CSAF List, (2) remove the overly narrow energy use qualifier associated with irrigation practices 430, 441, 442, and 533, and (3) expand the explanatory guidance in the Crosswalk to include more scenarios. For example, the following sentence could be added to the beginning of the 442 guidance: “Switching from flood irrigation to sprinklers where USDA-approved tools show quantifiable GHG reductions, where water is already delivered to fields with pressure, where water would be pumped with a renewable energy source, or where switching reduces the need for emission-producing field visits to open up headgates; or utilization of variable rate irrigation (VRI) technology … .”
These modifications to the CSAF List will allow funding to flow to practices that reduce GHG emissions, improve water quality, and help build drought resiliency. All these outcomes benefit our environment and our communities.
Thank you in advance for considering our comments, and for your continued commitment to ensuring that IRA dollars can quickly make their way to the ground in communities. For follow-up, please contact Tim Wigington (tim@thefreshwatertrust.org) and Dan Keppen (dan@familyfarmalliance.org).
[1] We recognize that GHG reduction benefits are one of many factors that need to be considered when making water on-farm management decisions. Other factors that need to be considered beyond GHG benefits include crop yield, affordability practicality, other benefits to the environment, and the economic bottom line. Accordingly, this analysis should not be read as a blanket statement that irrigation modernization is always the right choice, but rather that these practices should remain IRA-eligible “climate smart” practices available in the CSAF toolkit.
[2] While some like The Environmental Working Group have concluded that new irrigation systems likely do little or nothing to help in the climate fight, this conclusion appears publicly unsupported by data and peer-reviewed analysis.