- Author: Alli Rowe
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.
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.
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.
- Editor: Julie Clark De Blasio
- Author: Annemiek Schilder
June 1, 2019 – Plaza Park in downtown Oxnard was the site for this exciting event. It was a resounding success with an estimated 6000 attendees. Musical entertainment was provided by "the Beetles," while food trucks and booths provided festival fare including fried insects for the daredevils among the crowd. The University of California Cooperative Extension (UCCE) Office and UC Master Gardeners had neighboring booths that garnered a lot of interest. At the UCCE booth, children could study pinned insects in Anna Howell's collection, gaze through magnifying glasses at critters in compost, and learn how invasive shothole borers are destroying trees in Los Angeles and Ventura Counties. The Master Gardeners provided information about the Asian Citrus Psyllid (an aphid-like insect) that spreads the deadly Greening Disease to citrus trees and showed kids how to remove insects and spiders without killing them. Other booths featured giant beetles and tarantulas, had kids hold wriggling fly larvae, and told the public about ways in which insect pests are managed by biological and quarantine measures. This event showed that insects continue to be fascinating and fun for all ages!
- Author: Alli Rowe
I love cover crops. I really do. No, I don't think they are the solution to everything or that they work magic in every scenario. But for the scenarios they work in, they are marvelous. Why are these plantings so interesting, you ask? Well, let me tell you about my love interest with cover crops.
First of all, cover crops are one of the most cost effective ways to build soil organic matter. You can get cover crop seed for a few dollars a pound, grow it up, and terminate it once it goes to seed. All of that seed goes right back into the soil, giving a nice seed bank to reseed next season. Compare that to the cost of purchasing, transporting, and spreading mulch or compost and you have yourself a deal.
Cover crops can be selected for multiple benefits and to unique environments. Let's take an orchard system for example. In an orchard situated in certain temperature zones, there may be an increased risk of frost. Planting tall cover crops that come to maturity during the coldest days of the year put the orchard at greater risk for frost. Instead, this risk can be minimized by seeding low stature cover crops in January. The winter rains will assist in establishment, but the growth will be minimal during those frost-prone days of February. Come March and April, a fully established cover crop will provide erosion control and increased infiltration rates to keep rain onsite for the orchard.
Another thing to love about cover crops is their role in nutrient management. Nitrate leaching is a problem of excess fertilizer making its way below the root zone and into water systems. Think regulatory agencies, public health and environmental concerns, and paperwork. Grasses and brassicas are excellent nitrogen scavengers, helping prevent nitrate leaching to groundwater. These grasses and brassicas take up nitrogen and then slowly decompose, releasing that nitrogen back to the soil as a biologically available form for the cash crops to utilize. Legumes, on the other hand, work in an entirely different way to impact nitrogen. Utilizing nitrogen fixing nodules in their root systems, legumes fix atmospheric nitrogen and exude it as biologically available nitrogen for other plants to use. With a greater level of soil nitrogen available, less added nitrogen is required for optimal crop growth.
Weeds and pests. Carefully selected cover crops can use their super hero powers to combat villains that threaten crop viability. Want to suppress weed competition? Maybe plant a cereal rye or a mustard. Grow that up, knock it down, and create a nice mat to stifle weed growth. Aphids got you down? Try planting some legumes such as cowpea to attract lady beetles.
Soil structure. Oh, soil structure! Cover crops can provide multiple benefits here as well. Cover crop roots prevent erosion, keeping soil in place. In addition, they add organic matter to the soil as they grow and decompose. Roots of various cover crops, especially those in the daikon radish and sugar beet variety, have deep penetration and can break up compacted soil layers. In the process, cover crops increase soil porosity and infiltration, allowing water to move into and stay in the soil profile instead of running offsite. The change in soil structure to one of fluffier, porous, organic material provides habitat for increased soil biodiversity of microorganisms and decomposers. These guys help with nutrient cycling to maintain soil healthy and productivity. Over time, cover crops build soil tilth, soil porosity, soil organic matter, soil biodiversity, and overall soil structure that is easier to work with and produce in.
I could go on. The point is not that cover crops are the answer to everything, but rather that they provide multiple benefits for a good price. Cover crops are a low investment practice to test out when building healthy, resilient soils that will last for future generations of farmers.
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.
- Author: Alli Rowe
This week the California Department of Food and Agriculture released the much anticipated Healthy Soils Program awards. Statewide, a grand total of $12.48 million will be supporting 217 projects that build soil health, increase soil organic matter, and decrease greenhouse gas emissions through agricultural land management practices. On a national scale, this funding represents the country's largest investment in building healthy soils as a climate mitigation strategy. This is great news for farmers, ranchers, and the soils of California.
The program funds farmers and ranchers to implement practices such as cover crops, reduced tillage, mulch application, development of grazing management plans, compost application, and the establishment of windbreaks or hedgerows. The awards support both incentive projects and demonstration projects under the umbrella of the Healthy Soils Program. CDFA selected 194 incentives projects to receive $8.7 million in funding across 45 counties and 23 demonstration projects to receive $3.8 million in funding across 16 counties.
So, what happened in Ventura County? I am sure you are eagerly awaiting the local news! In our county, we have 1 demonstration project and 3 incentive projects that received funding. That is a huge increase from the previous round in which Ventura County only received 1 incentive grant. See below for details on the projects funded for the county.
Incentive Projects
Organization |
Brief Description |
Total Funding ($) |
Estimated GHG Reduction (MTCO2eq/yr) |
King & King Ranch |
Converting 32 acres to no-till and planting windbreaks. |
$6,794.94 |
12.6 |
The Abundant Table |
Increase cover crop rotation, plant hedgerows, and apply compost. |
$23,589.79 |
42.2 |
Clow Ranch |
Apply mulch to avocado and lemon orchards. |
$74,778.09 |
3.0 |
Demonstration Project
Organization |
Brief Description |
Total Funding ($) |
Estimated GHG Reduction (MTCO2eq/yr) |
Ventura County RCD + Limoneira |
Research the impacts of various compost and mulch applications on a newly planted lemon orchard. |
$249,546.00 |
21.4 |
For a full list of projects and project descriptions, please go to the websites for the CDFA Healthy Soils Incentive Program and the CDFA Healthy Soils Demonstration Program.
Stay tuned for updates on how these projects progress and opportunities to come see Healthy Soils in action in Ventura County!
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.
By Andre Biscaro
Join us on Thursday, June 12, 2019 from 9 am-10:30 a.m. at Crisalida Berry Farms in Oxnard for this important free field day.
• Learn how different nitrogen fertilizer rates and sources affect strawberry yield, fruit quality and shelf-life
• Visualize treatments effects on plots and discuss results
• 1.5 Continuing Education Units (CEU) applied for Certified Crop Advisers (CCA)
• Simultaneous Spanish translation available
Check out the flyer below for more information and map
Field Day flyer 6 2019