California Ag Network

Tag: Cover Crops

  • Last Chance for Free Cover Crop Seed from Project Apis m.

    There are less than 100 spots left for growers to take advantage of free cover crop seed from Project Apis m. Through their Seeds for Bees program.

    Running from April 1 to Aug. 31, Seeds for Bees encourages the adoption of cover crop to provide forage for bees in orchards in California and elsewhere. This has the added benefit of fixing nitrogen and other vital nutrients into the soil. The seed mixes available through Seeds for Bees are designed to bloom through critical parts of the year, when natural forage is scarce and pollinators need it the most.

    Learn more about Project Apis m. and their Seeds for Bees program here.

  • California Orchards Blossom with NRCS Help Managing Pests

    California’s Central Valley is a land of agricultural abundance, known for its incredible diversity of crops including fruits, vegetables and nuts. It produces approximately 25% of the nation’s food.

    But with plenty can come pests – in as many varieties and types as the crops grown in the region. Area farmers have worked with USDA’s Natural Resources Conservation Service (NRCS) to implement integrated pest management into their orchard operations with marked results.

    Sandra and Mike Smith of Smith Family Farm in Fresno, California, showed NRCS Chief Aubrey Bettencourt the benefits of the practices that they have incorporated with NRCS assistance as they toured their 36-acre almond orchard.

    Established in 1903, the farm is on the cusp of welcoming its fifth generation of farmers. By adapting their operations to increase conservation and sustainability practices, the Smiths hope to pass on a rich legacy to their young granddaughters.

    The Smiths highlighted the impact that integrated pest management practices – notably hormone disruptors – have had in their fight to combat navel orangeworms in their almond orchards.

    “We were at 17.1% loss of our almond crop two years ago because of the infestation of navel orangeworms,” Mike Smith told Chief Bettencourt. “Once we implemented the mating disrupters, we were able to bring our almond reject numbers down to 1.1%.”

    Navel orangeworms burrow into almond nuts to feed on the kernel, damaging the nut and impacting producers’ overall yield and harvest quality. Deploying pheromone-based mating disruption tools can reduce navel orangeworm populations by hindering male moths’ ability to locate females.

    The Smiths have also leaned on NRCS technical assistance to implement other conservation techniques to increase the health of their orchard. The family now prioritizes composting and increasing organic matter, guided by the knowledge gained through NRCS collaboration.

    Further north, Chinchiolo Farming Co., Inc., a family-run business located in Lodi, California, is managing orchards of a different kind while embracing similar production practices.

    Producer James Patrick Chinchiolo has worked to uphold a century-old farming legacy, started by great grandfather Italian immigrant James Joseph Chinchiolo. Chinchiolo has worked with NRCS to incorporate a number of conservation practices including cover crops, tractor replacements, orchard removal and soil incorporation.

    Like the Smiths, Chinchiolo has dealt with pest issues, incorporating a Biologically Integrated Orchard Systems (BIOS) approach in managing his orchards. The BIOS system aligns with NRCS principles, embracing the implementation of conservation practices like cover cropping, beneficial insect habitat, and compost application to keep pests at bay.

    “We aim to foster a more ecologically balanced environment within our orchards,” Chinchiolo said during his discussion with Chief Bettencourt. “We are focusing on minimizing our inputs and creating more habitat for beneficial insects to flourish to help control unwanted pests.”

    Conservation practices like cover cropping and compost application not only help pollinators flourish – a crucial part of growing beautiful cherries – they also protect the trees’ overall health, improving soil structure and water retention.

    After last summer’s heat impacted this year’s cherry crop, Chinchiolo is working to take additional measures to make his trees more heat resistant in preparation for next season.

    “Growing cherries is never predictable. But it’s always beautiful.” Chinchiolo said.

    Helping People Help the Land

    During her visit, Chief Bettencourt emphasized that the agency’s primary focus is to give producers the tools that they need to be the best producers that they can be – increasing their yield while stewarding the nation’s natural resources.

    “Producers are the solution, and we want to empower them by getting our highly skilled staff out in the field to provide technical support. We want to streamline our programs to work better and faster for producers,” she said.

    NRCS helps farmers, ranchers and forest landowners make critical investments in their operations and local communities by helping them implement proven practices to ensure all of America’s farms, ranches and private lands are economically viable and thriving.

    If you are interested learning how these programs can help you achieve your operational and land management goals, find your local USDA Service Center and get started today.

    Follow the Chief through our blog series as she meets with producers across the country to learn how NRCS has helped their operations. — By Debra Denhart, Public Affairs Specialist, USDA

  • Seeds for Bees Program Helps Growers Unlock the Benefits of Cover Crops

    Project Apis m.’s Seeds for Bees program is open and accepting application now through August. With support from several agricultural groups, including the Almond Board of California, the program is back again to help growers experience cover crop benefits in their orchard by providing them with free cover crop seed, nurturing a landscape that fosters both agricultural productivity and environmental stewardship.

    The Seeds for Bees program offers free seed support through Project Apis m. First-year participants are eligible for up to $2,500 worth of free seeds, while second-year participants can receive up to $1,500. Returning applicants can continue to benefit from discounted seed purchases through the program, ensuring ongoing support for seasoned growers.

    One of the program’s key strengths lies in its diverse seed offerings, tailored to meet the unique needs of various crops and farming practices. From popular mixes like the Pollinator Brassica, which blooms early to support almond cultivation, to specialized blends such as the Nitro Builder, designed to enhance nitrogen fixation, the program caters to a wide range of agricultural requirements.

    The benefits of cover crops extend far beyond their role in supporting pollinators. Improved water infiltration, often likened to a sponge, is one of the immediate advantages noted by growers. “Your soil is a lot like a sponge,” said Stetcyn Maldonado, manager of the Seeds for Bees program. “If you have a sponge that’s really open, you got all your pores in there and you can hold a lot more water and air than a sponge that’s squished. A cover crop really helps with getting your rainfall into your soil as quick as possible.”

    Addressing concerns about competition, Stetcyn reassures growers that cover crops, especially those offered through the Seeds for Bees program that are winter cover crops, are allies in weed suppression rather than adversaries to perennial crops. By occupying space and utilizing resources, cover crops naturally outcompete weeds, offering a sustainable solution to weed management and then are terminated before almond trees start growing again.

    With the application period open from April 1 to August 31, growers are encouraged to seize the opportunity and secure their spot in the program. “We’ve had a ton of applications already and the program is always increasing popularity,” Maldonado noted. “Seed is limited, so you want to make sure that your spot is secured,” The goal is to ensure timely delivery of seeds to growers’ doors, well before the optimal planting window from early to mid-October.

    Visit the Seeds for Bees website to learn more about the program and to apply for seeds. Additionally, upcoming videos featuring grower testimonies will offer insights into real-life experiences with cover crops and the Seeds for Bees program, providing a firsthand glimpse into its impact on agricultural practices. 

  • Weed Control During Pollinator Habitat Establishment

    Pollinator insects are essential to produce many economically and nutritionally important crops grown in the western USA. These crops include blueberries, almonds, sunflowers, cucurbits, and many others. Almond pollination in California plays a vital role in the apiary industry, driving beekeepers to haul huge numbers of bee colonies to California for the few weeks in late winter when almonds bloom. Bees are selective of the pollen and nectar they forage, and diverse floral resources can allow bees to forage according to their nutritional needs (Leponiemi et al. 2023). Planting pollinator habitat in natural areas, gardens, and agricultural land is one method of supporting bee health. Irrigated agricultural land in the western USA can be an excellent resource for bees during the dry summer when flowers are rarer. However, the resident weeds in these settings are often not of high nutritional quality for hungry pollinators. To make matters worse, pollinator habitat in agricultural fields can be choked out by competition from weeds. Our control plots from these studies (Figure 1) demonstrate that point effectively.

    Objective:

    The studies described here attempt to use herbicides to improve the chances for success in pollinator habitat establishment.

    Methods:

    Three locations in Oregon’s Willamette Valley were selected for studies. Two were hazelnut orchards watered with drip irrigation, and one was a field plot set up for sprinkler irrigation. Each location received different soil preparation. The first orchard location (Corvallis) was not tilled, and soil compaction issues were present. The second orchard location (Amity) was power-harrowed, so the top two inches of soil were loosened. The third location (Lewis-Brown Research Farm) was plowed and disked.

    All three locations were seeded in the fall with a set of flowering species with potential for pollinator habitat (Table 1).

    Table 1: Species and seeding rates used for pollinator habitat establishment in Oregon’s Willamette Valley.

    These species were planted in rows, and herbicide treatments were applied over the top perpendicular to planting rows (Table 2). Four herbicides were applied post-emergence, and the rest were applied one day after planting (pre-emergence). Glyphosate treatments were only included in the orchard trials. Experimental plots were set up as a randomized complete block design with four replicates, and each species was treated as a separate experiment. A crop oil concentrate at 1% v/v was included for Motiff (mesotrione) and Basagran (bentazon), while a nonionic surfactant at 0.25% was included for Matrix (rimsulfuron) and Quinstar 4L (quinclorac). All post-emergent treatments (and glyphosate) included ammonium sulfate (AMsol 1% v/v).

    Table 2: Trade name, active ingredient, and rate of herbicides applied to pollinator habitat species. Pre-emergent herbicides were applied at planting, and post-emergent herbicides were applied 30 days after crop emergence.

    In Amity, competition from perennial grasses resulted in poor stand establishment. A grass-selective herbicide (clethodim) was used, and the site was reseeded six months after the initial planting when soil conditions were appropriate.

    Results and discussion:

    Site differences.

    Drastic differences were seen between sites. Table 3 shows how crop coverage differed between the three sites for each species.

    Coverage at the Corvallis site was deficient for all species except hairy vetch.

    Several species did very well at the Amity location. Phacelia in the glyphosate plots was exceptionally well established due to glyphosate’s good control of perennial grasses that were not killed by the power harrow.

    Lewis-Brown (LB) plots had the best crop establishment initially. However, this location had intense pressure from perennial weeds, so the initial crop establishment did not translate to superior pollinator habitat. The plots at LB where Alion was applied produced a good stand of Canada thistle (Cirsium arvense) by the end of the trial, which the bees loved.

    Table 3: Crop Coverage for each species at each location is shown here. The values reported are from the treated plots with the highest coverage.

    Pre-emergent treatments

    Pre-emergent herbicides often had inconsistent pollinator species safety; however, several combinations seemed safe. Napropamide was safe for Phacelia, Gilia, Clarkia, and Lobularia, while flumioxazin and pendimethalin were safe for poppy (Table 5). All five species only had adequate crop establishment at two of the three locations. Hairy vetch establishment was improved by simazine applications at all three locations, but crop coverage was not significantly different from the untreated control for this species (Table 5). Figure 2 shows the treatment by species combinations that were sometimes safe versus the combinations that were consistently safe for the planted species.

    At the two orchard sites, glyphosate treatments were the best for Gilia, Phacelia, and poppy establishment (Table 5).

    All three trials were conducted on fine soils with organic matter content ranging from 2-7% (USDA-NCSS soil survey). The safety of pre-emergent herbicides for pollinator species establishment may vary depending on soil characteristics.

    Post-emergent treatments

    Post-emergent (POST) applications were challenging to evaluate for safety. Weed control efficacy was inadequate, and so often, crop establishment was not good enough to confidently assess crop injury.

    One exception was hairy vetch. This species exhibited good tolerance to a post-emergent application of Basagran, a result seen at all three locations. The results from two trials suggest that Clarkia tolerated POST applications of Quinstar. Not enough data were collected to conclude the other four species. See Table 4 for crop coverage data.

    Conclusions

    Site preparation was an essential consideration in our study. Soil compaction and perennial weed pressure must be addressed to have a successful pollinator habitat planting. It was also clear that pre-emergent herbicides can improve habitat establishment, but safety must be adequately established. This is especially true of different soil types and environments. In California’s Central Valley, pendimethalin has been seen to occasionally cause injury in poppy plantings, which is in contrast with this study. — By Marcelo Moretti (Oregon State University) and Ryan Hill (UC Cooperative Extension)

    Table 4: Spring crop coverage (%) from plots treated with post-emergent herbicides one month after planting, which happened the prior October. Missing data from Phacelia and Lobularia at LB is due to crop loss from frost injury.

    Table 5: Spring crop coverage for pre-emergent herbicide treatments applied just after planting, which happened the prior October. Phacelia and Lobularia experienced winter kill at the LB location, so reported data is coverage from December for that location.

    Figure 2: Crop coverage pictures from two months after planting the Lewis-Brown research farm show that the planted species (rows) tolerated several pre-emergent herbicides (columns). A black outline surrounds successful combinations seen in at least one of the other two trials. Combinations that were never seen to be successful again are surrounded by a red outline.

    References:

    Leponiemi, M., Freitak, D., Moreno-Torres, M. et al. (2023). Honeybees’ foraging choices for nectar and pollen revealed by DNA metabarcoding. Sci Rep 13, 14753. https://doi.org/10.1038/s41598-023-42102-4

    Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at the following link: http://websoilsurvey.sc.egov.usda.gov/.

  • New Report on Intersection of SGMA and Cover Crop Water Use in California’s Central Valley

    A multi-disciplinary authorship group of over 30 individuals has published a report comprised of literature review, policy analysis, and recommendations pertaining to the water impacts of cover crop practices in California’s Central Valley under the Sustainable Groundwater Management Act (SGMA).

    The report, entitled “Cover Cropping in the SGMA Era,” is the product of a convening process jointly developed by the California Association of Resource Conservation Districts (CARCD), California Department of Food and Agriculture (CDFA), Natural Resources Conservation Service of California (NRCS-CA), and University of California Agriculture and Natural Resources (UC ANR) and assembled by Sustainable Conservation.

    Cover Crops and their Potential

    Cover crops are non-income generating crops that are used to protect and improve the soil between regular annual crop production (such as tomatoes), or between rows of perennial tree and vine crops. The benefits of cover cropping include improved pollinator habitat, infiltration, water storage, carbon capture, and soil health, as well as decreased runoff and erosion – all vital factors in California’s changing agricultural context. These potential benefits are especially salient in the San Joaquin Valley (SJV), where groundwater challenges are more acute. Thus, this report evaluates the water implications of cover cropping practices to lay the groundwork for their adoption in the context of SGMA.

    Report Findings and Recommendations

    To understand the potential of cover cropping under SGMA, the report’s authors came together to answer the following questions:

    1. What are the impacts of cover crops on water cycles (both benefits and use) for California farms?
    2. How does SGMA management account for cover cropping and is it capturing cover crop benefits alongside their water use?
    3. How can we ensure that this practice remains available to growers where and when it makes sense?

    This report synthesizes the learnings from the collaborative initiative including 100+ multidisciplinary experts, a policy analysis, interviews with Groundwater Sustainability Agency (GSA) staff and consultants, and the expertise contributed by its 30+ authors. In light of these findings, the report advances a series of recommendations aimed at bridging critical knowledge gaps, enhancing the integration of cover crops into policies and incentive programs, and bolstering data infrastructure and other mechanisms to support sustainable groundwater management initiatives. One vital throughline is the need for additional guidance from the state to support local GSAs in facing the complex challenges of developing and implementing groundwater management strategies for their local watersheds. These measures aim to maximize the water benefits of cover crops within SGMA frameworks and promote sustainable water management practices crucial for the region’s agricultural resilience and environmental health.

    Side-by-side of Donny Hick’s almond orchard without (left) and with (right) cover crops after a big rain event

    Testimonials

    “Cover crops are one of the most popular practices we see farmers employ through our Healthy Soils Program,” said Karen Ross, Secretary of the CDFA. “Cover crops supply a host of benefits, such as helping to protect against soil erosion, improving soil health, crowding out weeds, controlling pests and diseases, and increasing biodiversity; and they can bring increased profitability as the number of other inputs are reduced. They also provide water benefits such as improved infiltration and reduced runoff. Yes, cover crops require a nominal amount of water to establish – and sometimes rainwater is sufficient — but the myriad co-benefits are worth it.”

    “This report is unique because the University collaborated closely with state agencies and private sector partners to ensure that the different perspectives provided both the best science available as well as viable policy options,” said Glenda Humiston, University of California Vice President for Agriculture and Natural Resources (UC ANR). “By taking a comprehensive view, we can advance recommendations for cover crop policy that help us meet multiple goals, manage our natural resources more effectively, and avoid unintended consequences.”

    “Cover crops are a valuable soil health practice that can help ensure the resilience of California farms to climate extremes,” said Sarah Light, UC Cooperative Extension Agronomy Farm Advisor. “As we balance the complexities of water and soil management, it is important to understand the role that cover crops play in an annual water budget so that they are not disincentivized in certain parts of the state. UC ANR expert participants provided science-based information during the convening sessions and co-authored the white paper. This paper can provide guidance to GSAs and policy makers who are charged with implementing SGMA in their regions.”

    View the Executive Summary

    View the Full Report

  • Timing Cover Crop Termination to Meet your Residue Goals

    Cover crops are used to address multiple resource concerns and can provide a wide range of conservation benefits including reduced soil erosion, scavenged residual soil nitrogen, weed suppression, and supplemental livestock forage. The carbon to nitrogen (C:N) ratio of the cover crop determines the durability of the cover crop residue.

    Durable cover crop residue can be desirable or undesirable depending on the scenario and the specific resource concerns addressed with the cover crop. For example, durable cover crop residue is thought to increase soil organic matter and reduce soil erosion. On the other hand, it may tie up soil nitrogen that subsequent crops need, especially early in the development of the crop. So, it’s not just the species of cover crop that determines the C:N ratio of the residue but also the timing of the termination of the cover crop. Cover crops terminated at an earlier growth stage have a lower C:N ratio in their residue than those terminated at a later growth stage.

    Cool season grasses are a popular component of cover crop mixes. Cereal rye (Secale cereale L.) is a commonly used cover crop with a C:N ratio as low as 30:1 and as high as 50:1. These ratios are based on plant maturity, but a common practice is to terminate cereal rye cover crops before maturity. To evaluate how C:N ratios of cereal rye varieties vary with termination timing, the NRCS Manhattan, KS Plant Materials Center conducted a study at Leonardville, KS in 2020-2021.

    Samples were taken from the varieties weekly from mid-March to late April to coincide with common commodity crop cover crop rotations.  All varieties developed their C:N ratio similarly both years. The C:N ratio was 12:1 in mid-March and near 24:1 by the end of April.  A practical application for using this data is: if durable cereal rye residue is not a specific goal and the potential tie up of soil nitrogen is a concern, terminate the cereal rye 200 days after planting, if a more durable residue is desired, delay termination of the cereal rye until 210 days or more after planting.

    For more information on C:N ratios of cereal ryes evaluated in this study refer to Early Spring Carbon to Nitrogen Ratios of Cereal Rye Varieties (usda.gov).  Technical information and guidance regarding cover crops and soil healthis available on the Plant Materials Program website or contact the nearest Plant Materials Center or plant materials specialist.  For additional information on specific species of plants mentioned, please see the USDA PLANTS database.