Progress report for FW23-423
Project Information
The biggest challenge that annual cropland farmers face in California is how to keep their soil healthy and productive at the end of the annual crop cycle.
What are the opportunities and challenges of incorporating summer cover crops and livestock on conventional annual farming systems?
We will be studying the various impacts of three different treatments utilizing summer cover crops. This will promote healthy soils, livestock, and our environment. In the areas promoted we also hope to have a positive social impact by reducing our carbon footprint by regenerating soils. We hope by showing we can keep our soil productive in the "off season" that more growers will implement summer cover crops to promote healthy soils and increase economic value by either grazing or baling. We will share the outcomes of our project with on site fields days, newsletters, and local grower meetings.
The objectives of this project are to:
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- Quantify the economics of three termination strategies for a summer cover crop including grazing, baling, and discing to incorporate residue into the field (control treatment).
- Quantify changes in soil health for three termination strategies for a summer cover crop including grazing, baling, and discing to incorporate residue into the field (control treatment).
Education and outreach objectives are to:
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- Demonstrate opportunities to profitability incorporate livestock into annual rotations.
- Reduce barriers to summer cover cropping and livestock incorporation by increasing knowledge and awareness of how to manage these practices.
- Increase communication between farmers and ranchers in the region to further opportunities for grazing on annual cropland.
- These objectives will be accomplished through:
- Outreach events: a field day will be organized at the farm to discuss the project. This field day will help meet all three objectives outlined above by 1) visually demonstrating how to manage livestock on cropland and providing information about the economics of each treatment; 2) Ted and Ben will present on their experiences and observations with the project including the logistics of managing animals in a rotation; unexpected challenges and opportunities; considerations for scaling up the practice; 3) these events will be advertised widely through UC Cooperative Extension and partner collaborator networks in order to ensure good attendance. At these events time will be dedicated to discussion on the challenges and opportunities for both farmers and ranchers of livestock integration. Sarah Light led a farmer-rancher discussion on livestock integration in annual systems in 2021 and this project will build upon that outreach work.
- Written communication. Findings from this project will be written up and shared via UC Cooperative Extension newsletters and blogs. In addition, a story about the project will be submitted for consideration to other relevant publications in the state to increase the reach of this work. Sarah Light will post a project summary on her UC Cooperative Extension webpage within one year of project completion. Educational and outreach objectives 1 and 2 will be met by this written communication.
- Presentations: Technical Advisors Sarah Light and Josh Davy frequently give presentation to grower audiences and will incorporate information about this project into relevant talks about soil health or grazing. These presentations will help meet objectives 1 and 2.
- Video presentations: Producer project leaders will produce a short video in the field on project observations during the course of the project. The target audience of this video will be farmers and ranchers. This video will be shared with regional producers and will help meet objectives 1, 2, and 3 of this project.
- April - May 2024
- Project Initiation - Soil Sample and Analysis , PI (Ted Kingsley), TA (Sarah Light)
- June 2024
- Before Cash Crop planting - Soil Sample and Analysis , PI (Ted Kingsley), TA (Sarah Light)
- July 2024
- Plant and Irrigate cover crops PI (Ted Kingsley), Ben Carter
- September - December 2024
- Rotate animals through planted cover crops , PI (Ted Kingsley), TA (Josh Davy) (Treatment 1)
- Weigh livestock periodically for average daily weight gain, PI (Ted Kingsley), TA (Josh Davy)
- Cut, swath, and bale summer crop , PI (Ted Kingsley), Ben Carter (Treatment 2)
- Chop summer cover crop , PI (Ted Kingsley), Ben Carter (Treatment 3)
- Cut and sample cover crop for dry matter and nutrition analysis , PI (Ted Kingsley) , TA (Sarah Light and Josh Davy)
- May 2025
- Soil Sample and Analysis , PI (Ted Kingsley), TA (Sarah Light)
- Conduct field days and presentations from project and report results, PI (Ted Kingsley) , TA (Sarah Light and Josh Davy)
Cooperators
- - Producer
- - Technical Advisor
- - Technical Advisor
Research
The California Central Valley has a long growing season, allowing for the opportunity to maximize crop diversity, soil coverage, and a living root, through incorporation of cover crops into the rotation. A standard management practice with summer cover crops is to disc and incorporate the cover crop. This treatment is the control treatment. The objectives of this project are to:
-
- Quantify the economics of three termination strategies for a summer cover crop including grazing, baling, and discing to incorporate residue into the field (control treatment).
- Quantify changes in soil health for three termination strategies for a summer cover crop including grazing, baling, and discing to incorporate residue into the field (control treatment).
Following summer cash crop harvest, a summer cover crop will be planted. This project evaluates three methods of terminating a summer cover crop: grazing, baling, or discing and incorporation. All treatments will be replicated three times. If there is no reduction in soil health, while providing an economic benefit, producers may be more likely to consider incorporating a summer cover crop into their rotations. Water is extremely limited in California and a summer cover crop requires irrigation for establishment and productivity. Understanding these tradeoffs is critical for farms in California. After summer cover crop termination, a winter cover crop will be planted in the fall, followed by a summer cash crop in the spring.
Objective one will be met by weighing animals before and after they graze each grazing treatment plot. The economics of baling treatments will be quantified based on the yield per acre and will be translated into a dollar amount based on the price of hay during the project year. The discing and incorporation treatment is assumed to have no economic return. Costs associated with each treatment will also be quantified to generate a budget/balance per treatment.
Objective two will be met through soil sampling at three points during the project year: prior to project in initiation, prior to spring cash crop planting, and one year after project initiation. All soil samples will be collected in the top foot of the soil profile by walking the plot in a W pattern to get one composite sample per plot. Baseline soil samples and soil samples one year after project initiation will be analyzed for total carbon, total nitrogen, organic matter, as well as other soil fertility measurements that are relevant to producers (pH, soil fertility, EC). Soil samples collected in the spring prior to cash crop planting will be analyzed for plant available nitrogen (nitrate) and soil biology assessments (Haney test). The goal of these mid-project samples is to assess any differences in soil that would be relevant to a farmer going into the cash crop season including nitrogen tie up. Bulk density samples will be collected at project initiation and one year after project initiation to quantify any changes in total carbon or total nitrogen. Soil compaction measurements will be taken once during the cash crop growing season when crop roots are actively growing. In addition, cover crop biomass will be collected from the control plots prior to cover crop incorporation. Three meter square quadrants of biomass will be collected and analyzed for total nitrogen and total carbon to measure how much carbon and nitrogen is being added back to the soil on a per acre basis.
We don't have results to share because we had to get an extension and redo the project this year (2024).
Research Outcomes
Lessons learned.
Here we will include several lessons learned from our project last year (2023-2024)
- We chose sudan grass as a main ingredient in our summer cover crop for several reasons. Those reasons include fast growing species, substantial biomass production, low cost of seed, and high feed quality. However in our project environment the sudan is not an acceptable variety because of prussic acid produced by the plant during senescence. Moving forward we will consider other species such as grass or perhaps small cereal grains to replace the sudan.
- We are integrating the summer cover crop during the time of year row crops are being harvested, managing labor and resources are a logistical challenge.
Education and Outreach
Participation Summary:
We requested an extension on our project because the sudangrass in our summer cover crop mix produced prussic acid, which is toxic to livestock. We got the extension and plan to execute the project again this coming summer. We met with the project team and decided to wait to have a field day until we have results to share.
We are working on a mid-project summary to share as a newsletter article this spring.
We don't have results to share yet but will quantify and share at the end of the project.