Since 2016, soybean farmers have quickly adopted dicamba- and 2,4-D-ready crops in their fight against herbicide-resistant weeds. However, the expanded use of these herbicides during the growing season has led to an increased threat of drift damage for neighboring specialty crop growers. Several high-value crops can be damaged by concentrations of 1/300 the labeled rate or lower. Crops with especially high sensitivity to dicamba and 2,4-D include grapes, tomatoes, and soybeans that are not engineered for dicamba-resistance. Recent legal issues have limited the use of three dicamba products for the 2020 growing season, but 2,4-D and other dicamba products are still in use and will continue to pose a risk in areas with diversified or organic production.
A new fact sheet series is available to help specialty crop growers prepare for and respond to possible dicamba and 2,4-D drift. The series provides tips for being proactive, detailed steps for documenting and responding to damage, and a brief background on why dicamba and 2,4-D have been especially problematic. A Frequently Asked Questions fact sheet highlights various concerns pertinent to specialty crop producers. The series sought input from a variety of crop and herbicide specialists across the United States, as well as state regulatory agencies.
Fact sheets are available online at go.osu.edu/ipm-drift.
Preparing for drift
“Vigilance and communications are the two big things,” says Ohio State weed specialist Doug Doohan, “Knowing who your neighbors are, talking to them about your plans, talking to them about their plans, being aware of who’s doing what on the land and when.”
But who is your neighbor when it comes to drift? Just how far can dicamba drift travel? Most spray droplet drift will move short distances. This type of damage is generally limited to adjacent fields. However, dicamba and 2,4-D are likely to drift as a gas or via a temperature inversion. Temperature inversions can be especially damaging, moving suspended pesticides in a fog-like layer for longer distances.
“There’s all kinds of circumstantial evidence of much greater movement,” says Doohan. “When you’re talking inversions, if an inversion is motivated by a 2-3 mph wind, it could go miles—especially if the conditions persist through the evening.”
Doohan has helped investigate several drift cases and was one of the co-authors for the new fact sheet series. He encourages growers to establish a Standard Operating Procedure to prepare for a drift incident, just as they might for food safety concerns. He also stresses the importance of documenting suspected drift quickly, thoroughly, and repeatedly. The new fact sheet series offers detailed suggestions for these activities.
“If you see something, document it,” he advises. “Use your cell phone. You can always delete unneeded photos later, but you can’t go back in time and get the picture you wish you had taken.”
The new fact sheet series was cowritten by specialists at The Ohio State University and Purdue University, with support from the North Central IPM Center Working Group on Herbicide-Drift Risk Management. The working group organized in the fall of 2019 and plans additional projects in the coming year, including more resources and an anonymous survey of specialty crop growers to better assess the extent and frequency of drift damage throughout the north central region. The North Central IPM Center serves Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin and is supported by the USDA National Institute of Food and Agriculture through agreement 2018-70006-28884.
Results are available online for the 2019 Michigan Organic Soybean Variety Trials. The trials included 43 varieties – 20 of which are commercially available. Results include details on source, variety, maturity group, hilum color, percent oil, percent protein, maturity days after planting, plant height, yield and multi-year data.
Previous years’ organic trials for soybeans, edible beans, and other agronomic crops can be found at the Organic Farmers of Michigan website.
Ohio State Corn and Oats Variety Trials Planned for 2020
Ohio State is planning organic crop variety trials this year for both corn and oats. Organic farm manager Gerald Reid reports 15 varieties of oats have emerged and that corn trials should be planted soon.
Previous Ohio State organic corn variety trials can be found online as well:
Sales of foliar fertilizers have skyrocketed in the last several years, particularly among organic dairy farmers. Foliar products are readily available, easy to store, and many products are approved for organic use and formulated to provide humates, microbiological products, micronutrients, and other popular treatments. Advocates of these products say they offer an environmentally friendly, efficient, and cost-effective way to apply fertilizers. Yet much of the recent research done on foliar feeding has been unable to reliably document benefits to production.
Louceline Fleuridor has spent the last two years studying foliar feeding as part of her Ohio State master’s degree program. She partnered with organic dairy farmers to measure the response of forage and soils to post-cutting foliar fertilization on 19 on-farm sites. As with previous studies in Ohio, Fleuridor found no consistent evidence of benefits from using foliar feeding products.
"In foliar feeding, you apply fertilizer through the leaves, which is contrary to the traditional knowledge that plants will absorb nutrients through their roots,” says Fleuridor, explaining that leaves' primary function is thought to be photosynthesis. "It raises some questions."
On Thursday, December 19, Fleuridor met with participating farmers and Ohio State specialists for a discussion of the research trials and results.
Partnering farmers began the meeting by sharing their experiences with foliar products. Wayne county dairy farmer Jeff Miller began experimenting with foliar feeding on one of his pastures five years ago. He decided to spray half of his pasture to see what would happen and because he couldn’t afford to spray the whole field. But when he noticed how much quicker his herd began to graze in the foliar fed area, he decided he couldn’t afford not to spray the whole field. Other farmers relayed similar experience, noting increases in crop yield, forage health, palatability, and harvested hay quality that coincided with the use of foliar feeding.
Yield gets a lot of attention in studies, but quality and palatability are also important, especially on dairy farms where forage is not the end product. Past studies have noted other advantages to foliar feeds, including decreased nutrient runoff, better absorption efficiency of micro- and macronutrients, reduced instance of disease, and, in a 2000 study on wheat, increased grain protein content.
"Forage quality is where we really expected to see changes, but we didn't," said Ohio State soil fertility specialist Steve Culman, who provided technical assistance on the project.
Fleuridor's study examined a variety of forage quality measurements, including in-field measurements for sugar content (Brix), as well as lab analysis for crude protein, stem:leaf ratio, fiber content, relative forage quality, net energy of lactation, and estimated milk/ton.
In addition to sharing individual and overall test results with the participating farmers, Fleuridor also spent time explaining how researchers use randomized plots and statistics to separate actual treatment differences from differences that happen randomly or from variations in the field. Fleuridor noted that there were some differences between the treatment and control in the studies, but the results were inconsistent and didn’t reveal a cohesive pattern of increased yield, plant health, or milk production for the sites in this study.
Culman cautions farmers to inform themselves before using foliar feeds. “If you’re looking at adding these products, look at the formulation and know what you’re getting. Foliar products tend to supply only a small amount of nutrients.”
Most of the farmers in the study plan to continue using foliar feeding, feeling that these products have caused improvements on their fields. They did note mixed results with some products and a need for additional labor. Several of the participants also stressed that other soil problems need to be fixed before turning attention to foliar feeds.
As for Fleuridor, she feels there are many factors that could have contributed to the mixed results in this study, including weather and soil conditions when the products were applied. She recommended that future studies use a consistent forage composition, and suggested a focus on clover may be advisable, based on farmer feedback.
This study was sponsored by The Ohio State University Paul C. and Edna H. Warner Grants for Sustainable Agriculture, Organic Valley FAFO (Farmers Advocating for Organic), and SoilBiotics. Organic Valley FAFO is currently accepting grant proposals for on-farm research projects. The deadline is February 15, 2020. Read more: https://www.organicvalley.coop/why-organic-valley/power-of-we/farmers-advocating-organics/
|Ohio State researcher Louceline Fleuridor applied foliar feed treatments at spring green up and 10 days after each cutting. Applications were made in the mornings when temperatures were below 75 degrees F.|
A smaller than usual corn harvest is underway in Ohio. A smaller than needed portion of the harvest continues to be organic.
According to annual acreage reports from Mercaris, a company specializing in market data and services for organic and non-GMO, the 2019 harvest will see a record number of organic grain acres, despite the notoriously poor spring planting season (1). But the firm also predicted a 12% decrease in actual organic corn yields, compared to 2018, which will lead to increased imports and costs for organic livestock farmers.(2)
For decades, consumer demand for organic food has grown annually by double-digits (3). While still a comparatively small portion of overall agricultural production, organic corn acreage in the U.S. increased by more than 55% between 2011 and 2016, driven mainly by demand from organic dairy farms (4). Despite the large increase in production, organic grain was imported to the U.S. in 2016, indicating the potential for future growth (5, 6). Currently, Ohio ranks in the top 5 states for number of certified organic corn growers, and in the top ten for acres harvested (7). However, relatively little is known about the management practices of these farms.
As part of an interdisciplinary study on soil balancing, Ohio State researchers surveyed certified organic corn growers in Ohio, Michigan, Pennsylvania, and Indiana in the spring of 2018. These four states collectively represent one-third of all U.S. organic corn growers and produce about 20% of the nation’s organic corn.
Responses show the majority of organic corn growers in this region are dairy farmers. More than half of the organic corn grown in 2017 was used as on-farm livestock feed. Most (70%) respondents harvested corn as grain corn; 36% harvested corn as silage (with some doing both). Other uses were rare. A surprisingly large number (nearly 2/3) of the growers use horse-powered equipment, indicating they are likely members of Old Order Amish or similar Plain communities.
The survey examined the use of soil amendments, crop rotations, cover crops, various tillage and cultivation strategies, yields, selling costs, and management priorities. Manure and compost were by far the most common practice, used by 89% of all organic corn growers. Other amendments were used by fewer than half the growers. Tillage practices were chosen for weed management, but most other management decisions focused on soil health.
Reported yields varied widely, ranging from 25 to 250 bushels per acre for grain and 5-34 tons per acre for silage. According to the data collected and estimated from survey responses, very few farmers lost money on the fields reported on for this study.
Farmers with more years of experience raising crops organically tended to have higher net returns on average, suggesting that economic performance can be expected to improve over time for transitioning farms. About 40% of respondents had less than five years of experience farming organically.
Researchers received a 57% response rate (859 responses), yielding a margin of error of 2%.
This work is supported by Organic Agriculture Research & Extension funding grant no. 2014-51300-22331/project accession no. 1003905 from the USDA National Institute of Food and Agriculture. Read more at go.osu.edu/orgcorn.
Ah spring! The war against weeds begins anew. The first major skirmish of the growing season should happen before planting. The stale seed bed technique is an often over-looked practice that can be used before planting. It works by first encouraging weeds to sprout and then killing them when they are young and most vulnerable. For organic growers, a stale seed bed can replace the effects of a pre-emergence herbicide. And when used properly, it can contribute to both short-term and long-term weed management.
Weed control can be handled with short-term or long-term approaches. Short-term management focuses on controlling weeds during the first part of crop growth when weeds are more likely to affect crop yields. Long-term weed management, however, works all season-long to deplete weed seeds from the seedbank (the reservoir of viable weed seeds in the soil). Whichever approach you take, using a stale seed bed is a great cultural weed control technique.
To use the stale seed bed most effectively, start several weeks before planting. An initial cultivation kills any emerged weeds that have overwintered. It also brings weed seeds to the surface where exposure to light and oxygen stimulate germination. Depending on the weather and types of seeds present in the soil, weeds may sprout up overnight or over a few weeks. When weeds have germinated and are still small and young, they are easy to kill with a second light cultivation. This process is then repeated as needed and as time allows. As few as three cycles of light/ shallow tillage can reduce the number of subsequent weeds noticeably. For fields and gardens with very heavy weed infestations more cycles of repeated tillage over a few years will be needed. Using a stale seed bed may push back your planting date; but in the absence of weed competition, the crop will have more access to water and sunlight and be able to make up for lost time.
Keys to Success
- Do not allow emerged seedlings to grow large. It is best to till lightly just as the first seedlings are emerging as this and the earlier ‘white thread’ stage are the most susceptible to desiccation. The more time new weeds have to develop roots, the harder they become to kill with a shallow cultivation.
- Keep the cultivation shallow to avoid bringing new weed seeds to the surface. The implement used to stir the soil should not go deeper than 2 inches with most of the stirring in the top inch.
- The technique is dependent upon having adequate soil moisture. Under drought conditions preparation of a stale seedbed may require irrigation to stimulate weed seed germination.
- Deeper initial tillage can be used to bury an existing weed problem. Tillage, especially when done with a disc or a power tiller, distributes the previous year’s weed seeds throughout the top 6 inches or so of soil. In contrast, an inversion tillage that turns sod upside down will place last year’s seeds 6 inches or so under the surface. From there they are unlikely to emerge unless further discing or lighter tillage moves them closer to the surface. Used skillfully, a deep inversion plowing followed by stale seed bed can put a serious surface weed problem out-of-sight and out-of-mind, at least until the next time the field is plowed deeply.
Stale Seedbed is most effective when it’s part of a zero weed threshold system.
The common short-term approach to managing weeds(which weed scientists usually call the “critical period approach”) is to control weeds aggressively during the first 4-6 weeks after the crop is planted. This 4-6-week period is the critical period during which crops stands are established and yield is secured. Afterwards weeds are of less threat to production; therefore, many farmers scale back control efforts. However, weeds that grow before and after the critical period are still a problem. If allowed to flower and set seed, they will be planting a future crop of weed problems. A long-term approach to weed management, called zero weed seed threshold, requires constant diligence and removal of all weeds before they produce seeds--even after harvest. Research indicates that 3-4 years of using this approach will result in a field with relatively few weeds, provided weed seeds are not introduced from without the field (in seed, irrigation water, on equipment, etc.).
Both short-term and long-term approaches have benefits and drawbacks, many of which depend on a farmer’s individual goals, crops, and available resources. A new online tool from Ohio State allows farmers to think through various weed control approaches in the context of their own individual situations. For those looking to make changes to their weed management, the Organic Weed Decision Making Tool, shows pros and cons of various strategies over time and gives steps to implementing new tactics. Learn more at go.osu.edu/eco-weed-mngt.
Recordings are available from the 27th Annual Conservation Tillage and Technology Conference, held in Ada, Ohio, in March 2019. This two-day event brought together speakers in a variety of subject areas – many of which will be of interest to organic farmers.
Videos are available on the conference’s You Tube Channel.
Here are some of the offerings:
Cover Crop Panel: Addressing Cover Crop Seed Issues
Sarah Noggle, OSU Extension, Paulding Co., Moderator; Jay and Ann Brandt, Walnut Creek Seeds; Don Grimes, Ohio Seed Improvement; Cody Beacom, Bird Hybrids
Protecting Identity Preserved Crops In The Field:
Managing Pollen Drift to minimize contamination of Non-GMO Corn
Dr. Peter Thomison, OSU Extension Corn Specialist
Enhancing Mycorrhizae And Metarhizium Fungus
Jim Hoorman, USDA-NRCS, Soil Health Specialist
What Management Practices Most Influence Soil Health In Corn Production?
Dr. Christine Sprunger, OSU Assistant Professor, SENR
Enhancing Beneficial Insects With Pollinators
Dr. Stephanie Frischie, Xerces Society Agronomist / Native Plant Materials Specialist, Plymouth, WI
Can Weeds Be Managed With Calcium Amendments?
Dr. Doug Doohan, OSU Professor, HCS, and Andrea Leiva Soto, OSU PhD Student, HCS
Elephant In The Room: Why Do So Many Farmers Practice 'Soil Balancing' Despite The Lack Of Scientific Evidence?
Dr. Doug Jackson-Smith, OSU Professor, SENR, and Dr. Caroline Brock, OSU Senior Research Associate, SENR
The Effects Of Manipulating Ca:Mg Ratios On Ohio Crop Yields And Soil Health
Dr. Steve Culman, OSU Assistant Professor, SENR, and Will Osterholz, USDA-ARS
Weather Pattern Effects On Conservation Practices
Dr. Aaron Wilson, OSU, Byrd Polar and Climate Research Center
Return On Investment With Using Gypsum
Dr. Subbu Kumarappan, OSU Associate Professor, ATI
Gypsum Is More Than Calcium: Summary Of Ohio Field Crop Responses To Sulfur
Louceline Fleuridor, OSU MS student, HCS
Weed control without chemicals means fewer options. In fact, weed control is often cited as a reason farmers decide not to pursue organic certification. Although ecological weed management tactics are available, research reveals that many organic farmers do not take advantage of them.
This may happen for a variety of reasons. All weed control methods come with pros and cons, which vary depending on specific growing conditions, cropping systems, and farmer priorities. For example, in a low-value crop, investing time into mechanical or hand-weeding may not be economically feasible. In poorly draining soils, frequent cultivation may lead to soil compaction and drainage problems, or field conditions may make it difficult to add a cover crop into the rotation.
To help farmers consider these trade-offs, a team at The Ohio State University and Michigan State University has developed an online tool to present different weed control strategies, along with their historic long and short-term performance.
How it works.
The Organic Weed Manager tool collects specific information on growing conditions and farmer priorities. The program then compares the users’ current strategy with alternative approaches, showing the predicted impacts over time across diverse objectives (weed seedbank, costs, soil health, etc.). For those who want to consider a new approach to weed control, the tool also suggests specific steps to take.
The online tool is easy to use and gives individualized results. The tool is not meant to make management decisions for you, but rather to provide an opportunity to consider and compare alternative strategies, while reflecting on individual priorities and values. In this way, the research team hopes to lower barriers to on-farm experimentation and improve adoption of organic weed management techniques.
The Organic Weed Manager software is free and available at organicweedmanager.com. Completing the tool takes approximately 20 minutes. Users may save their progress and return later to complete it. Users can access the tool from a desktop or laptop computer, tablet, but not from a phone. Farmers and farm advisors are encouraged to use the tool and provide feedback for further development. The tools itself contains an area for evaluation and comments.
For more information about organic weed control options, including case studies, resources, and ongoing research projects, visit go.osu.edu/eco-weed-mngt.