Authors: Alli Rowe, UCCE Ventura County and Niki Mazaroli, Strategy Research Science 

There has been much buzz and renewed interest recently in planting trees as a tool to combat both the causes and impacts of climate change. But what role do trees play in climate-smart agriculture?

With respect to building healthy soils, tree canopy and leaf litter can provide protection against wind erosion and temperature extremes. Tree roots can help stabilize soils, increase nutrient cycling, and improve soil biota representative of a healthy soil system. The incorporation of trees and shrubs on agricultural landscapes, known as agroforestry, blends the practices of forestry and agriculture and can provide many ecological and economic benefits.

Photo by Jet Kim on Unsplash

The USDA defines agroforestry as “the intentional combination of agriculture and forestry to create productive and sustainable land use practices” [1]. In theory, it really is this simple: adding trees or shrubs to an agricultural landscape. In practice, like most things in agriculture, it is more nuanced and, of course, site specific. Agroforestry includes a suite of practices with varying degrees of complexity that yield systems also of varying degrees of complexity. The most common agroforestry practices in the U.S. are: alley cropping, silvopasture, riparian buffers, windbreaks, and multi-story cropping (also referred to as forest farming). 

Like many of the practices that fall under the header of climate-smart agriculture, agroforestry is both old and new. While the term agroforestry is relatively new, agroforestry has been practiced for millennia, yielding diverse, multistoried food forests in both temperate and tropical climates. The recent interest in agroforestry of the last few decades has been driven in part by the desire to apply the benefits of perennial agriculture to address some of the challenges of row crop and animal agricultural systems. 

When considering transitioning to agroforestry practices, it is crucial to understand in advance how the incorporation of perennial woody plants will impact your existing operation. Select trees and shrubs that will grow well in your climate and the specific conditions of your farm, and will complement - not compete with! - existing crops or pasture. 

Windbreaks Photo by Adrien Olichon on Unsplash

In addition to plant selection, site design and management are also key. For example, where you plant trees or shrubs on your farm in relation to other crops or other elements of your farm can determine whether there is synergy or competition for water and nutrients. Site design can also determine the need for different types of management, such as in alley cropping systems where the widths of the “alleys” between rows of trees must factor in the size of any machinery used.

A local example of agroforestry in action is at King & King Ranch in Fillmore. The King family received a Healthy Soils Program Incentive Grant award to establish a windbreak along a 32-acre plot that is transitioning out of vegetable cultivation. The windbreak will protect the soil from the intense Santa Ana winds that sweep through the valley, establish living roots, sequester carbon in the woody biomass of the trees, and provide habitat for local pollinator and bird populations.

Photo of King & King Ranch Credit Gemina Garland-Lewis.

We will be highlighting more about agroforestry practices and the efforts of local producers in future blog posts, so stay tuned!

[1] USDA National Agroforestry Center. Agroforestry Practices. 2019. Available online: https://www.fs.usda.gov/nac/practices/index.shtml (accessed on 31 August 2018).

Climate smart agriculture encompasses management practices that increase soil carbon sequestration, reduce greenhouse gas emissions, improve yields and efficiencies, and promotes climate resilience. The California Department of Food and Agriculture (CDFA) supports three funding opportunities in climate smart agriculture: the Healthy Soils Program, the State Water Efficiency & Enhancement Program, and the Alternative Manure Management Program.  

In a collaborative partnership, CDFA and UC Agriculture and Natural Resources have teamed up to support 10 community education specialists throughout the state to provide technical assistance and outreach for the climate smart agriculture programs. As one of these technical assistance providers, my role is to promote and support the adoption of these programs in Ventura County. If you are interested in working with me, please contact me at amrowe@ucanr.edu.

Lisa Tate is coming into her own in helping manage her family's farms in Ventura County. In addition to avocado and citrus, she is one of the pioneers of coffee growing in the coastal California, a fledgling industry in specialty crops. Growing high quality coffee has been on the rise, thanks to Frinj Coffee creating a collaborative of growers with the goal of figuring out how best to produce the best product. With the treats of climate change, development, and disease threatening much of coastal California's agriculture, coffee provides a beacon of light as a potentially successful next generation crop. Lisa's interview below sheds some light on her family's farming operations and her role in fostering the future of farming.

Lisa and the coffee crew. Photo credit Lisa Tate.

Grower Q & A

1. Can you provide a brief introduction of yourself?

My name is Lisa Tate and I am a 6^th generation farmer in Ventura County. My family has seven farms spread throughout Santa Paula, Saticoy, and Fillmore. I earned my B.S. degree in Agricultural Business at Cal Poly, and my M.P.A. (Master of Public Administration) from Walden University. I currently split my time between farming and taking care of my two sons ages six and nine. While I am very much in the learning stage of farming, I hope to get more involved as my children become more independent.

2. What do you grow?

We grow Lemons, Avocados, Valencia Oranges, Mandarin Oranges, Pomegranates, and Coffee.

Coffee at Rancho Filoso. Photo credit Lisa Tate.

3. How long have you been farming?

I have been directly farming for a year and a half, but I have been somewhat involved in family ranching for about 20 years.

4. What are you doing on your land to improve soil health?

We add fertilizers, use natural avocado leaf mulch, spread our pruning mulch, and manage water runoff.

5. What current issues are you facing as a farmer?

As a farmer in California, we face the rising cost of labor, increased concern about water availability, fluctuations in commodity pricing and consumer demand, tightening regulations, and challenges with trustworthy and available consumer information.

6. What opportunities do you see in farming in Ventura County?

The weather is fantastic, the soil is great and I think we can grow pretty much anything. I am particularly excited about growing specialty coffee in the region and see it as a sister to California's wine growing operations. I love the idea of women grown and harvest coffee for our family farm and am actively working to see that vision through.

Coffee growing at Rancho Filoso. Photo credit Lisa Tate.

King & King Ranch operates out of Fillmore, California and has been growing citrus and avocados since 1913. Alana King, fourth generation of the King family, grew up visiting their grandparents on the ranch and four years ago returned with their partner to steward the family land. The face of the next generation of farming, Alana embraces practices that build soil health, keeps an eye on the economics of the operation, and looks forward to integrating conservation management practices to care for the land into the future. In the interview below, Alana shares with us a bit about the family farm.

Alana and a prized avocado. Photo credit Gemina Garland-Lewis.

1. What do you grow?

Mainly avocados and citrus and love diversity in our farm. We grow 9 varieties of avocados, almost 30 varieties of citrus, and a smattering of other crops such as pomegranates, persimmons, figs, culinary herbs, mangos, bananas, olives, and soon-hops.

A diversity of flavor from the ranch. Photo credit Alana King.

2. What has worked on your land to improve soil health?

We have entirely stopped using Roundup on weeds. Instead, we are weed whacking and mowing in an effort to control them and give the soil microbes a chance to get healthy. In some areas we have been able to apply mulch under the trees which is excellent at suppressing weeds. The mulch also results in some beautiful soil once it has time to break down so we view this as a great soil health practice for our ranch. 

We're also experimenting with cover crops to build soil organic matter, provide pollinator habitat, control weeds, and improve nutrient cycling. The cover crops in between trees is a really nice alternative to the weeds. We see bees all over the clover and it has out-competed the grasses and other weeds that were there before.

3. What has not worked?

The clover can grow right around the height of our irrigation sprinklers so we still have to weed whack to clear irrigation for the trees.  

Persimmon trees on the ranch. Photo credit Alana King.

4. What current issues are you facing as a farmer? 

In Ventura County we face extreme heat waves that are intensifying and becoming more frequent with climate change. As a farmer, there is always ongoing weed management, pest control, and time constraints to deal with. Additionally, we are figuring out the balance of direct marketing that generate better prices versus working with packing houses that result in lower prices, but a quick turnaround.

5. What opportunities do you see in farming in Ventura County?

It's incredible that we can grow just about anything in Ventura County. I wish I saw more restaurants showcasing the bounty that is grown all around them. There are a couple who do a great job, but by and large most places don't make the effort. Or if they do, they don't mention it on their menus. There's huge opportunity here for growing the local food movement.

Alana and Kai. Photo credit Alana King.

6. Have you used the University Cooperative Extension as a resource? If so, how?

Absolutely!! From advising on farm operations, to attending educational events, there have been great resources within the UC Cooperative Extension system. We have had help in applying for both the Healthy Soils Grant Program and the State Water Efficiency and Enhancement Program. 

Support your local farmers! To learn more about King & King Ranch and where to find their delicious produce, visit: https://www.kingandkingranch.com/

King & King Ranch. Photo credit Gemina Garland-Lewis.

Cover crops in avocados. How do you select species? When do you seed? Do they even work? What benefits do you notice? What are the management issues associated with cover crops? These were all questions addressed at a grower field day seminar entitled, “Avocado Nutrition and Cover Crop Usage” at Pine Tree Ranch. Hosted by the California Avocado Commission and presented by Ben Faber and myself from UC Cooperative Extension, the cover crop portion of the seminar culminated in a grower panel of three cover crop veterans. On the panel was Carl Stucky, a seasoned avocado grower in Carpinteria, Mike Sullivan, an orchard manager who dabbles in both organic and conventional, and Chris Sayer, owner of Petty Ranch in Saticoy. So, what did we learn?

 Cover cropping history?

All three of the growers on the panel had been cover cropping for over 20 years. As Carl Stucky put it “Cover cropping is not new. People have been cover cropping for thousands of years.” But how you cover crop and why is completely unique. Chris Sayer started cover cropping to alleviate soil compaction issues that were killing lemon trees. Mike Sullivan was inducted into cover cropping managing Valencia trees suffering from poor soil health and water infiltration. Carl Stucky started cover cropping on a property that suffered from severe soil erosion and loss.

Species selection?

Different cover crops can address different issues. Initially, Chris focused on deep rooted crops such as sugar beets and daikon radish to break up soil compaction. Recently, he has been using grasses such as triticale to build biomass and increase soil organic carbon. Carl aims for a variety of rooting types and diversity of plants to keep beneficial insects around. “I look for a range of responses and benefits, it is all cumulative”, he stated. All growers mentioned mixing it up, aiming for rotating diversity, and using selective covers to address specific needs. Agricultural crop rotation provides benefits such as soil fertility, nutrient cycling, and erosion control. A permanent tree orchard can't be rotated, yet diversity in cover crop selection allows growers to gain benefits of crop rotation. 

Triticale and Lamb-Hass. Photo credit: Chris Sayer

Benefits?

Cover crops provide a multitude of benefits based on species selected and issues being addressed. For growers in Ventura County, improving water infiltration is a noticeable benefit that everyone relates to. All growers reported issues of runoff prior to cover cropping and have seen dramatic improvements in retaining water in the soil. For a drought prone area and sensitive avocado trees, this could be the difference in surviving a July with a 120 degree heat wave or not. Pack out comparisons offer subjective records of yield increases on cover cropped bocks. And notable improvement of soil structure offers a compelling case for cover cropping benefits. Using soil map data, Chris Sayer estimates his orchard was around 2% organic matter prior to cover cropping. After decades of dedicated cover cropping, he now brings soil samples in with organic matter topping 5.7%. That is almost unheard of in Ventura County. All of that organic matter improves soil structure, tilth, water infiltration, and microbial communities to support healthy trees. For a long-term investment in cover crops, it can be tricky to specifically cite one benefit over the other. Mike Sullivan spoke to the challenge of putting a line item on a spreadsheet relating to cover crops saying, “How do you measure change in yield? Well, that is not necessarily why you cover crop. You cover crop because it makes sense.”

Problems?

The word of the day is management. As with anything, if you don't manage appropriately, issues will arise. In the case of avocado orchards, some of these problems can come in the form of irrigation entanglement from greedy cover crops, fat gophers snacking on your greens, thirsty cover crops sucking your water supplies, or providing a nice place for weeds you don't like to grow. These are all considerations and managing cover crops efficiently plays into how prevalent these problems are. As with any system, it is all about trial and error and using a curious mind to manage well.

Take home message.

Cover cropping is a fine balance of art and science. There are guides, resources, and research to inform decision making about what to cover crop and when, but there is no hard and fast answer. The success lies in choosing the right cover crops to address specific issues and managing them as they work within a unique system.  Cover crops are successful when the grower is interested in feedback, experimentation, and learning. This could mean manipulating seeding dates based on weather, terminating cover crops based on tree needs, getting creative with seed mixtures that fit the orchard. At the end of the day, it is all about finding creative practices to improve the overall functioning of the orchard and being adaptable to the future ahead.

Cover Crop in Vineyard. Photo Credit: University of California.

Climate smart agriculture encompasses management practices that increase soil carbon sequestration, reduce greenhouse gas emissions, improve yields and efficiencies, and promotes climate resilience. The California Department of Food and Agriculture (CDFA) supports three funding opportunities in climate smart agriculture: the Healthy Soils Program, the State Water Efficiency & Enhancement Program, and the Alternative Manure Management Program.

 In a collaborative partnership, CDFA and UC Agriculture and Natural Resources have teamed up to support 10 community education specialists throughout the state to provide technical assistance and outreach for the climate smart agriculture programs. As one of these technical assistance providers, my role is to promote and support the adoption of these programs in Ventura County. If you are interested in working with me, please contact me at amrowe@ucanr.edu.