Using high-frequency, real-time nitrate data to understand the potential for cover crops to improve storm resiliency in the face of a changing climate

View the project final report

Commodities

Practices

• Crop Production: cover crops, nutrient cycling, nutrient management, water management
• Production Systems: agroecosystems

With a rapidly growing global population, ensuring both food security and access to freshwater is critical. Thus, research is needed on conservation practices that strike a balance between sustaining productive agriculture and minimizing the downstream impacts of nutrient loss, including harmful algal blooms and contaminated drinking water supplies. Winter cover crops have been shown to retain nutrients on fields, and in turn reduce nitrate (NO₃^--N) loss from soils, especially during vulnerable periods such as spring snowmelt and runoff. However, the efficacy of cover crops in buffering the impacts of extreme events, such as winter and spring storms, is understudied, and these events can cause significant nutrient losses from agricultural land. In fact, the majority of annual NO₃^--N loss occurs during the largest storms, but the role of conservation to mitigate these losses has yet to be explored. Understanding the relationship between cover crops and storm NO₃^--N export will be crucial in sustaining crop yields as storm intensity and frequency is predicted to increase in the North Central Region in the future. We propose a study in which we will use real-time sensing equipment (Submersible Ultraviolet Nitrate Analyzers; SUNAs) to quantify the effects of cover crops on storm NO₃^--N export in two agricultural watersheds planted with contrasting levels of cover crops (~25% versus ~70% of croppable acres). Data from SUNA sensors offer an opportunity to study NO₃^--N loss and export dynamics during storms using high-frequency data. We will successfully translate our results to our partners in each watershed, including producers, county Soil and Water Conservation Districts, and government stakeholders. Such opportunities will allow us to convey the benefits of implementing cover crops as a conservation practice that imparts resilience to storms events. We will evaluate our progress via monthly data downloads and maintenance, routine data analysis, quarterly progress reports, and the dissemination of our results to project partners. The outcomes of this project will continue to provide data-rich support regarding the potential benefits imparted from cover crop implementation, and their role in building a sustainable cropping system that prevents negative environmental impacts.

Learning Outcomes:

1. Producers and landowners, along with resource managers, such as the Soil and Water Conservation District (SWCD) staff, The Nature Conservancy (TNC), and the USDA National Resource Conservation Service (NRCS), will be provided with data that supports the role of cover crops in providing resilience against nutrient loss during storm events. We will quantify these effects by comparing storm NO₃^--N export in two watersheds with contrasting levels of cover crop implementation: Kirkpatrick Ditch Watershed (KDW) with ~25% coverage and Shatto Ditch Watershed (SDW) with ~70% of croppable acres in cover crops. Results will be published in a peer-reviewed journal and shared at farmer field days and stakeholder meetings in both watersheds, allowing us to translate research outcomes and data to broad and diverse audiences.

Action Outcomes:

1. Farmers will adopt cover crops at higher rates in order to add resilience and prevent NO₃^--N loss from their fields as storm events increase in frequency and intensity over the next few decades. Our work will provide data highlighting a novel benefit of cover crops – storm resilience – that can support agricultural productivity by keeping nutrients on fields even when subjected to more severe storms.
2. Using our results, SWCD staff, NRCS managers, and other non-landowner stakeholders will encourage and advise large-scale adoption of cover crops by landowners. We have established a strong outreach network via previous and sustained USDA funding over the past seven years, which will provide us with ample opportunities to share our findings with audiences regionally.