Center for Regenerative Agriculture and Resilient Systems

Legume Research for Healthy Agroecosystems

Cover crops have become increasingly popular in California because of their contributions to improved soil health, and cool season cover crops have sparked interest as a result. Of the cool season pulses used in cover crop mixtures, fava bean (Vicia fava L.) and pea (Pisum sativum L.) express high nitrogen fixing capacity and have strong potential to reduce grower reliance on nitrogen fertilizers. These legumes are also popular food and protein sources around the world because of their contribution to reducing health issues associated with high cholesterol, diabetes, and cardiovascular disease. Our team has obtained roughly $1M in research grants and launched an extensive research program to study the potential benefits of these crops in northern California. Drs. Zakeri and Brasier at Chico State lead the research in collaboration with researchers in the Departments of Food Science and Business at CSU Chico, USDA-ARS in Pullman, UC Davis, CSU Fresno, and the Crop Development Center at University of Saskatchewan in Canada.  We also work closely with local producers including Lundberg Family Farm, Terra Nux LLC., and Chico Flax. The program has provided numerous opportunities for undergraduate students to conduct research on legume species for healthy soils and foods. Below is the list of our active and upcoming projects:

Screening Fava Bean Germplasm for Genotypes with Enhanced Biological Nitrogen Fixation

This study was funded by the California Department of Food and Agriculture (CDFA) and CSU Agriculture Research Institute (ARI) (2018-2021):to investigate variation for agronomic quality, disease resistance, plant morphology, and biological nitrogen fixation traits in a diverse panel of 63 fava bean accessions from 25 countries. The trial was conducted at CSU Chico, CSU Fresno, and Lundberg Family Farm over multiple growing seasons with the primary objective of identifying suitable fava bean varieties for cover crop mixtures. The findings will also help guide ongoing fava bean breeding efforts by characterizing available plant materials and by identifying traits that are associated with improved crop performance. The projects outcomes resulted in securing a second CDFA grant to test the findings of the first project so that is an ongoing project now.

fava bean plantsStudy of Potential Benefits of Fava Bean for Dual Purpose Food and Cover Crop

This Western Sustainable Agriculture Research and Education funded project aims to estimate the economic value and quantify potential soil nitrogen benefits of cover crop fava bean subjected to one or more fresh pod harvests. The trial is being conducted at CSU Chico, Terra Nux, LLC., Chico Flax, and Lundberg Family Farm over multiple growing seasons to quantify economic benefits of fresh pod harvests and soil health. In addition, this multi-disciplinary project will allow us to prepare and introduce foods using fresh fava bean pods to Chico community. Field trials were concluded Fall 2021 and samples are still processing as of this writing. 

Study of Nitrogen Contribution of Field Pea from Shoot and Root to Soil Nitrogen

Unlike many other plant nutrients, nitrogen is highly subject to loss from the soil system. Rapid nitrogen mineralization results in the conversion of soil organic nitrogen to nitrate that is readily lost from the soil. This loss may result in degraded ecosystems (e.g. harmful algal blooms and eutrophication) and cause groundwater contamination. However, nitrogen sources with a high carbon to nitrogen ratio undergo slower rates of nitrogen mineralization and are less likely to contribute to nitrate pollution. In this study, we characterize a field pea population that was developed at Crop Development Center at the University of Saskatchewan for below- and above-ground nitrogen composition. We have been measuring nitrogen mineralization rates of pea shoot and root tissue over the growing season of the following crop. The results are expected to help direct future cover crop breeding by establishing strategies to develop plants with decomposition rates that are more suitable for sustainable farming.

Cover Crop Project

Funded by CDFA (2020-2023): This project aims to study the performance of small seeded fava bean genotypes in cover crop mixes. Currently, bell bean (a fava bean variety) is grown in cover crop mixes, which has large seeds. Replacing bell bean with small- seeded fava will save in seed costs and make it much easier to plant the seed mix with grain drill. One pound of bell bean yields about 450 plants where small-seeded genotypes can produce over 1000 plants. This project is an extensive collaborative project between Chico State, CSU Fresno, Cal Poly Pomona, NRCS at Lockeford, Vilmorin Seed at Monterey, and Arizona State. The team just finished planting trials at these locations and Chico State will lead to complete them all. The project will train three graduate students (two in Chico and one in Fresno). It has also involved several undergraduate students in Chico, Fresno and Pomona.

Alley Cropping in Young Orchards

Funded by ARI (2020-2023). This project aims to promote alley cropping as a sustainable farming practice in California. In this project the team works with Buttle County farmer Dax Kimmelshue in Durham, CA. Preliminary observations were presented at the American Society of Agronomy conference (A Creative Economy for Sustainable Development) in Salt Lake City. They showed that alley cropping is less likely to impact water availability of orchard tree and tree water status.

Students present findings at a conference

Students present findings at a conference.

Alley Cropping Conference presentation slide

Alley Cropping presentation slide.