Cover crops offer many potential benefits to growers. For example, they can improve water infiltration, reduce erosion, and provide habitat for pollinators and other beneficial insects. 

But how does a grower figure out which cover crop species would work best for the specific conditions and concerns on their field? 

Of course, it's a good idea to start off by talking to a local NRCS planner or Cooperative Extension farm advisor. There is also plenty of information available on the internet and in printed publications about different cover crop species – but it's not all in one place. 

To help growers and planners sift through the available information and pick which cover crops will both provide the benefits needed and will survive in the specific conditions of their fields, I have been working on a cover crop selection tool since this past July. 

I used the CalFlora eVegGuide and the UCANR cover crop database as jumping off points and the Southern Cover Crop Council's cover crop selection tool as inspiration. 

To determine if a given cover crop will work for a specific field, the tool asks the user to provide the following information:

• The USDA hardiness zone of the field. The USDA has divided the country into hardiness zones based on average winter temperatures. The lower the number of the hardiness zone, the colder the place.  
• How much water the cover crop will receive. This is an estimate, especially for growers who will plant winter cover crops and depend entirely on the rain. If you can provide some irrigation water to the cover crops during their growing season, then include that in your estimate. 
• When the cover crop will bloom. Most growers will terminate their annual cover crops during peak bloom, to maximize growth and bee forage but minimize the likelihood of the cover crop turning into a weed. If you are planning on planting annual crops into the cover crop residue, leave a couple weeks between cover crop termination and cash crop planting to allow the residues to decompose. 
• How much salinity does your soil have? This can be a major inhibitor of plant growth and most cover crops cannot tolerate high or even moderate salinity levels. 
• What is your soil's pH? Like cash crops, cover crops have a specific range of pH values in which they can thrive. 
• Does your soil flood often? Some species can tolerate poor drainage conditions better than others. 

The other questions in the tool ask the user to rank the importance of various cover crop benefits to their operation. The benefits listed on this tool are: 

• Compaction reduction (improves water infiltration)
• Residue persistence (acts as a mulch)
• Erosion control
• Weed control
• Nematode control
• Attract pollinators
• Attract other beneficial insects
• Fix nitrogen
• Scavenge nitrogen (reduces nitrate leaching)
• Scavenge P and K (reduces nutrient contamination of waterways)
• Forage quality

To test the selection tool and see if it will provide good options for your operation, go to http://cekern.ucanr.edu/CDFA_Grants/HSP_Grants/Cover_Crop_Selection_Tool/.

Questions or comments? Reach out to Shulamit Shroder at sashroder@ucanr.edu.

During these unprecedented times of having to practice social distancing, the University of California Cooperative Extension's (UCCE) Climate Smart Agriculture -Community Education Specialists (CES) are still here to help you! We have continued to diligently provide technical assistance to farmers and ranchers interested in applying for the California Department of Food and Agriculture (CDFA) Healthy Soil Incentive Program (HSP) grants.

Since CES are currently limited in their ability to visit farms and met one-on-one with applicants they have been having to get creative in the way they can provide technical assistance. For example, a few CES have restructured their outreach efforts to focus on presenting regular HSP Zoom workshops instead of in person workshops, as well as hosting weekly virtual office hours over Zoom where applicants can log in and ask questions. Of course, contacting CES via email and phone is always an option.  

With that said, there is still an opportunity for farming operations to apply for the CDFA 2020 HSP Incentive grant; CDFA will be accepting grant applications until June 26, 2020. The Healthy Soils Program funds California implementation of conservation management practices that improve soil health, the sequestration of carbon, and the reduction of atmospheric greenhouse gases. HSP is a competitive grant with the maximum award of $100,000 that funds 28 eligible soil management practices, such as cover crops, whole orchard recycling, compost application, and nutrient management just to name a few. 

 If you are interested in applying don't hesitate to reach out to one of the CES near you for more information and technical assistance.  

Community Education Specialist Contact List

Vineyard with mustard cover crop in Shafter, California

Growers throughout the country and around the world plant a wide range of cover crops for a variety of reasons. Cover crops can reduce soil compaction, improve water infiltration, improve soil structure, and feed soil microbes: they encourage a healthier and more diverse soil ecosystem.

To see how cover crops would do in the dry southern San Joaquin Valley, climate smart CES Shulamit Shroder planted 5 common cover crop mixes at the UC research farm in Shafter, CA last November.

The plan was to hold a field day in March, to show local growers what these cover crop mixes looked like and how they could fit into their agricultural operations. 

The COVID-19 pandemic had other ideas, though. Instead of hosting a field day, she created a guide to the cover crop mixes, which is posted here. 

The cover crop mixes were:

-       Annual Plow Down Mix: fava beans, field peas, common vetch, and cayuse oats

-       Erosion Control Mix: annual ryegrass, barley, and crimson clover

-       Soil Cracker Mix: triticale, peas, white mustard, daikon radish, and common vetch

-       Clover Mix: rose clover, crimson clover, medic, balansa clover, Persian clover, berseem clover

-       Mustard Pollinator Mix: canola, white mustard, yellow mustard, and daikon radish

She planted each mix in an open field and in between table grapevines, to demonstrate the feasibility of including cover crops in a perennial cropping system. 

Click on the link below to see how the various cover crop mixes performed! 

Authors: Alli Fish and Niki Mazaroli, Strategy Research Science

Silvopasture is the intentional and intensive combination of trees, forage, and livestock on the same piece of land. The applicability and potential benefit of silvopasture to both ranchlands and orchards – two agricultural landscapes that dominate the region – adds to its promise as a climate-smart agriculture practice in Santa Barbara and Ventura Counties.

Over 80% of land in Ventura County and over 90% in Santa Barbara County is either being grazed or has the potential to be grazed. [1] And while silvopasture systems will not be suitable for all of the nearly 2 million acres of rangeland, silvopasture has great potential to support both livestock production and ecological health in the region.

What qualifies as silvopasture?

To put it simply, there are two approaches to establishing a silvopasture system: adding trees to pasture or adding animals to tree systems. Tree systems can include natural forests, timber plantations, and orchards.A key piece to the definition of silvopasture according to the USDA is that the combination of pasture, trees, and animals must be intentional and managed as a system, as opposed to “individual practices that occur coincidentally together or managed independently.” [2]

A key piece to managing a productive silvopasture system is rotational grazing, a livestock and pasture management practice that has been shown to greatly improve soil health when implemented correctly. Rotational grazing is also essential to maintaining the health of the pasture and minimizing damage to trees, especially young trees. Once trees are established and above browsing height, which varies depending on the grazing animals, this is less of a factor. However, the combination of animal and edible tree crops triggers important food safety regulations that must be considered early on in the design of any silvopasture system. (See “Regulations” below.)

Example of silvopasture. Photo credit National Agroforestry Center.

What are the potential benefits of silvopasture as a climate-smart agriculture practice?

The NRCS recognizes silvopasture as a multi-purpose conservation practice that can:

• Provide forage, shade, and/or shelter for livestock.
• Improve the productivity and health of trees/shrubs and forages.
• Improve water quality.
• Reduce erosion.
• Enhance wildlife habitat.
• Improve biological diversity.
• Improve soil quality.
• Increase carbon sequestration and storage.
• Provide habitat for beneficial organisms and pollinators. [3]

In terms of a producer's economic bottom line, silvopasture can be a way of diversifying revenue. For example, the shorter-term income from grazing livestock can buffer or offset the upfront cost of establishing trees and shrubs onto existing pasture. [4]

Cattle finding shade through silvopasture practices. Photo credit David Hazen on Flickr

Challenges and considerations

While formulaic in its definition, the actual practice of silvopasture is extremely site-specific, like most things in farming and ranching. The limitations of the land and the market opportunities available will inform the desired and required tree crop, forage, and livestock of the system.

And while there is consensus on the potential benefits of silvopasture, there isn't one single model – one combination of trees, forage, and livestock – that can inform all silvopasture operations.

Instead, there are many factors to consider when planning a silvopasture system, and most of them are interrelated:

• Regulations: Regulations are particularly tricky for silvopasture systems producing edible tree crops (i.e. fruit and nut trees). To comply with the GAP and NOP standards, raw manure cannot be applied 90 day before harvest of crops not in contact with the ground (i.e. many fruits crops) and 120 day for crops in contact with the ground (i.e. all row crops, and some tree crops). Farms with annual revenue greater than $500,000 and/or that sell majority of product beyond 275 miles must also comply with additional regulations as part of the Food Safety Modernization Act (FSMA). [5] Note that some packinghouses have agreed to only take fruit that is GAP certified. It is important to understand where any edible crops you will be producing will be sold and any associated food safety requirements before beginning or converting to silvopasture.
• Management skills and labor: Livestock producers must learn to manage trees, and, conversely, growers must learn to care for livestock. Additional infrastructure (potentially lots of fencing!) and labor to start up and maintain a rotational grazing system.
• Tree selection and system design: Depending on your existing operation and goals, you might prioritize fast growing trees that produce forage and aren't as delicate to livestock damage; or you might select tree crops or timber trees that are slower growing but have the potential to generate more revenue over time. Whether or not you own your land and, if you lease land, the terms of your lease may also influence the trees you chose to plant and your silvopasture plan overall.
• Source of forage: Will the trees and shrubs be a source of the forage or another crop to sell? Or both! Unharvested fruit and nuts can be consumed by livestock and a source of increased soil fertility when deposited as manure.

 Are you practicing silvopasture in Santa Barbara or Ventura counties? If so, let us know! We are interested in learning more about the opportunities and challenges that local producers face when implementing and managing these systems. 

 If you have plans for integrating silvopasture on your farm to help meet your soil health goals, consider applying for funding through the California Department of Food and Agriculture's Healthy Soils Program. Grant applications are expected to open early February 2020, you can stay up to date with email notifications and by checking the website: https://www.cdfa.ca.gov/oefi/healthysoils/. If you have questions or would like technical assistance on the grant process, please contact your local technical assistance provider at http://ciwr.ucanr.edu/Programs/ClimateSmartAg/TechnicalAssistanceProviders/. 

Plantings of trees as an example of silvopasture. Photo credit National Agroforestry Center.

Citations:

[1] California Gap Analysis Project “GAP”: California Fish and Wildlife Service and UCSB

[2] Brantly, S. What Silvopasture?—Working Trees. USDA National Agroforestry Center; 2013. Available online:https://www.fs.usda.gov/nac/assets/documents/workingtrees/infosheets/WhatIsSilvopastureInfoSheetMay2013.pdf. Accessed on 10 Dec 2019.

[3] USDA NRCS. Silvopasture (Code 381) Conservation Practice Standard. Pennsylvania. 2016. Available online: https://www.nrcs.usda.gov/wps/PA_NRCSConsumption/download?cid=stelprdb1255015&ext=pdf. Accessed on 1 Dec 2019.

[4] USDA NAC. Silvopasture. USDA National Agroforestry Center. 2019. Available online: https://www.fs.usda.gov/nac/practices/silvopasture.php. Accessed on 1 Dec 2019. 

[5] Gabriel, S. Silvopasture: A Guide to Managing Grazing Animals, Forage Crops, and Trees in a Temperate Farm Ecosystem. Chelsea Green Publishing, 2018.