Photo Credit: Shelby Gruss

Agronomy & Agroecology

This page provides information on the ongoing research on integrating forages to enhance resiliencey.

Research Projects

Our experiments have been carefully designed to benefit from ongoing and new research comparing the effectiveness of annual and perennial forage systems in promotinh soil health, biodiversity, and yield. We will evaluate three distinct systems: corn-based systems with alfalfa or integration with other perrenials, wheat-based systems with perennial and annual forages, and grazing systems with perennial and annual, or with perennials with increasing level of diversity, across different locations in the US. New and ongoing experiments will be meticulously evaluated and will include an assessment of insect biodiversity at specific sites. The data collected through this work will contribute to the accuracy of important models. See below for information on some of the studies being conducted.

Corn-Alfalfa Intercropping System (MI)expand_more

The system of this field experiment was designed for silage corn. Our hypothesis is that combining corn and alfalfa will increase soil health, require less N fertilizer, and improve land use efficiency, thus enhancing sustainability. Alfalfa and corn were seeded during the same year in the same field. One cutting of alfalfa hay was taken in the spring before the corn was planted, with potentially a second alfalfa hay cutting to be taken in the fall, after corn harvest. Corn was seeded in 60-inch rows with 9 alfalfa rows between the corn rows. The alfalfa growth was managed with glyphosate application for corn emergence. Variable N rates were applied to determine the N credit received from alfalfa.

Wheat-Alfalfa Rotation (ND)expand_more

We evaluated various crop rotation options for wheat production. Our hypothesis is that introducing diversity and perenniality increases farm-system sustainability and resilience. A traditional wheat-soybean rotation was compared with a wheat-alfalfa-alfalfa-alfalfa rotation.

Cover Crops and Grazing (FL)expand_more

This project aims to promote the adoption of cover cropping while minimizing nitrogen inputs into integrated crop-livestock systems. Our hypothesis is that leaching of nitrates to ground water will result. We examined row crops with no cover crops or grazing, row crops with cover crops, and both conditions with and without grazing. Treatments also included varying N fertilizer rates to determine the optimal combination to reduce nitrates leaching to groundwater while achieving desired crop production outcomes.

Environmental Impact Assessment

We’re conducting a meta-analysis to compare the environmental impacts of perennial and annual systems across diverse regions and ecosystems. Our goal is to establish standardized Life Cycle Assessment (LCA) methodologies. We’ll evaluate existing data, compare annual and perennial systems, and select a suitable crop-soil simulation model. This model will simulate carbon, nitrogen, and phosphorus cycles, including nutrient loading estimations to water sources.

Using the chosen model, we’ll develop a comprehensive LCA, considering multiple impact categories such as global warming potential, eutrophication, acidification, ecotoxicity, and more. We’ll quantify environmental improvements in perennial systems and express results per hectare, per dollar, and per unit of feed value. These findings will be discussed alongside economic assessments and stakeholder input, with an uncertainty analysis of LCA results. Data and results will be shared through platforms like the USDA-NAL LCA data commons and the forage data hub, fostering broader understanding and collaboration.

Photos

Planting corn into an alfalfa stand.
Alfalfa growing in between corn rows.

Forage Datahub

We are creating an online searchable database, specifically for sustainable agricultural intensification and diversification, especially regarding forages. We combined existing forage databases to create the first national forage database.

If you woud like to add your forage data to the Forage Datahub, please contact Amanda Ashworth. Email: amanda.ashworth@usda.gov

Publications

Framework to Develop an Open-Source Forage Data Network to Improve Primary Productivity and Enhance System Resiliency

-A.J. Ashworth, L. Marshall, J.J. Volenec, M.D. Casler, M.T. Berti, E. van Santen, C.L. Williams, V. Gopakumar, J.L. Foster, T. Propst, V. Picasso. Agronomy Journal

This study discusses the importance of utilizing legacy data repositories to prevent redundant research, enhance knowledge synthesis, and improve agricultural system productivity. The focus is on creating an online searchable database, specifically for sustainable agricultural intensification and diversification, especially regarding forages. The authors outlined the process of developing a community-driven forage database (Forage Data Hub) using various datasets encompassing different timeframes, spatial scales, and species. The steps include defining the data requirements, standardizing and structuring the data, creating a data thesaurus and model, and designing a web interface for database access.

This study demonstrates the value of curating diverse datasets by analyzing forage system resilience during extreme weather events. This was done by comparing the standardized yields to the yields during low-precipitation years. The results show that perennial systems outperform annual systems in terms of yield under challenging weather conditions. The development of the Forage Data Hub highlights the advantages of collaborative data sharing and curation, offering a way to assess sustainability and to promote practices that enhance ecological intensification and resilience to climate variability.

Diverse perennial circular forage systems are needed to foster resilience, ecoystem services, and socioeconomic benefits in agricultural landscapes

– Picasso, V.D., M. Berti, K. Cassida, S. Collier, D. Fang, A. Finan, M. Krome, D. Hannaway, W. Lamp, A.W. Stevens, and C. Williams. Grassland Research

In the current agricultural landscape, which is dominated by annual crop monocultures, vulnerabilities to extreme weather events, soil degradation, water and air pollution, biodiversity loss, as well as negative impacts on human health and social equity, have become pronounced. In pursuit of enhanced resilience, stability, and a broader range of ecosystem services, we advocate for a pragmatic framework that places diversity, perennials, and circularity at its core. This innovative framework has the potential to drive land transformations that effectively address the sustainability challenges facing agriculture. However, navigating the obstacles posed by policy, economic, and social barriers necessitates a transdisciplinary approach to equitable knowledge production.

For more information on all our articles. Click on the button below for our entire library.