Implementing potential climate‐smart practices through diverse partnerships

Societal Impact Statement Climate change is one of the greatest threats to society, negatively impacting agriculture and crop yields. Globally, agriculture is also one of the largest greenhouse gas (GHG) emitting sectors. Climate‐smart practices that are developed through diverse partnerships with scientists and practitioners are needed to decrease GHG emissions. We implemented and modelled climate‐smart practices (diverse cover crops and innovative manure management). Our results highlight the need to optimize amendments to ensure sustained yield with lowered GHG emissions. Moreover, we completed a successful collaboration that led to a farmer's adoption of recommended practices. Integrating these outcomes into policy frameworks could ensure that financial and technical resources are directed toward practices proven effective under local conditions. Summary Rural, agricultural‐based communities face a multitude of increasing risks due to anthropogenic climate change, such as drought, flood, and heatwaves. These events lead to crop declines or total losses depending on severity and timing. Innovative and adaptive agricultural systems can play a pivotal role in addressing these climate‐induced impacts. However, it is increasingly recognized that transformative solutions are often regionally specific and require data‐driven insights to inform best management practices. Many times, agricultural research is not conducted with input from producers, and results are not relevant to implementation. We developed a diverse partnership between the Nez Perce Tribe, University of Idaho, USDA Natural Resource Conservation Service, Clearwater County Soil and Water Conservation District, Idaho Soil and Water Conservation Commission, and a private landowner to test real‐world potential climate‐smart practices. We used experimental field‐based observations and process‐based modelling to examine a farm‐level implementation of climate‐smart practices intended to increase soil health while decreasing greenhouse gas (GHG) emissions. Agricultural practices tested in this study were chosen through collaboration with all of the partners. Practices included testing five cover crops (Timothy Hay and four cover crop mixes) across four amendment types (no amendment, raw manure, actively composted manure, and chemical fertilizer). In field trials, we observed a trade‐off between cover crop quantity and quality; crop yield was 40% higher in plots with chemical fertilizer, while the nitrogen content of plant biomass was 16% greater in plots amended with raw manure. The manure amendment type had no effect on crop yield. To determine the efficacy of manure type in reducing GHG emissions, we compared cumulative GHG emissions for the business‐as‐usual scenario (BAU; Timothy Hay with chemical fertilizer) with each of the other amendments. In each of our future scenarios, we experimentally manipulated the amount of manure that was added throughout the simulation. All raw manure scenarios reduced emissions compared to BAU, while only the lowest application rate of actively composted manure reduced emissions compared to BAU. These results provide guidance on the efficacy and nuances of climate‐smart practices in this region, including optimizing timing and amounts of additions along with yield, while providing a framework for a successful collaboration that led to farmer adoption of recommended practices.