I’m fascinated by research, but frequently frustrated by how long it takes to reach end-users. Farming moves at a speed infinitely faster than research, but for good reason. Research helps us sort through casual observations and one-time coincidences for deeper truths and connections. Because we give more weight to research than observation, it requires more accuracy, rigor, and time.
But it all starts with good observations and questions. Which is why I’m so excited to attend the OEFFA Conference this month! It’s a great opportunity for disciplines to cross paths – farmers, growers, suppliers, researchers, program administrators—and share information.
At the OEFFA conference or otherwise, please feel free to be in touch. I’d love to talk about some of the research topics you’re interested in. We’re working with OEFFA and Central State on ways to promote organic research collaboration between farmers and scientists in Ohio. One opportunity listed below is the Warner Grant program (a long-time project of OSU's Agroecosystem Management Program), which is taking proposals until March 1. Also below are a few recent research updates, along with other resources and events coming up in the next month.
-Cassy Brown, OFFER program manager
Organic Dairy Herd Health Management in Ohio.
According to the most recent USDA survey, Ohio ranks 4th in the number of certified organic dairies and 14th in production. Organic dairy producers have distinct perspectives, approaches, challenges, and experiences when managing herd health, but few studies have documented these. Ohio State researchers used semi-structured interviews to examine herd health management for the organic dairy industry in and around Ohio. Interviews examined decision factors relating to disease prevention and treating infectious diseases, along with organic dairy - veterinarian relationships. Read more: https://go.osu.edu/orgdairy19.
Organic Corn Trial Results Available
The Ohio Organic Corn Performance Test evaluates certified organic corn hybrids for grain yield and other important agronomic characteristics. The tests were conducted on certified organic fields at Apple Creek (West Badger Farm) and Wooster (Fry Farm) in Wayne County and were intensively managed for nutrients and weed control using organic practices. See results at https://ohiocroptest.cfaes.osu.edu/organiccorntrials/.
Vegetable Pathology Lab 2021 Trials
The OSU Vegetable Pathology Lab carried out an active field research program in 2021, with full field trials spread across three Ohio research sites in Wooster, Celeryville, and Fremont and three bioassays for downy and powdery mildew management. As part of their 2021 trials, the lab tested biological control products, and disease-resistant varieties to manage diseases of tomatoes, peppers, cucumbers, pumpkins, cabbage and collards. You can read the research trial results at Plant Pathology Series 2022_Veg Pathology Research Rpts 2021_final. (These trials were not conducted on organic certified plots. Always refer to your certification agency’s approved list of products.)
43rd Annual OEFFA conference Feb 12, 17-19
The Ohio Ecological Food and Farm Association Conference is February 17 to 19 in Dayton, Ohio, and February 12 online. More than 1,200 folks from throughout the state attend this conference. Funds are available through SARE to cover Ohio State educators’ registrations. Contact Mike Hogan or Suzanne Mills Wasniak if interested in attending or displaying materials. Registration closes February 10. Learn more at https://conference.oeffa.org/
Ray Archuleta "Soil Health and Regenerative Ag - Feb 24 in West Liberty, Ohio
Missouri farmer, retired soil health researcher Ray Archuleta will discuss soil health and regenerative agriculture at the West Liberary Salm High School. This event includes a dinner at 5:30, with presentation at 6:30. The event costs $20 and includes CCA credits. Deadline to register is February 21, but space is limited. Read more at http://go.osu.edu/archuleta
Field Futures—Ohio – Workshop Event on Feb 22
Curious how climate change connects to your farm? Consider attending the inaugural Field Futures-Ohio workshop planned for Tuesday, February 22nd from 10-6PM at the Lodge at Scioto Grove. This unique event will use participatory design exercises to explore alternative climate futures for Ohio. There is no cost to attend, but space is limited and registration is required. Food and supplies provided. Register at go.osu.edu/fieldfutures by Tuesday, February 15 or contact Forbes Lipschitz for details (603 738 2144 or email).
Soil Health webinar series – March 3
The OSUE 2022 soil health series concludes with “Hot Topics-What's the Future of Soil Health?” on March 3, 8-9 a.m. A variety of soil health researchers will briefly discuss their current and ongoing work. Come with your questions and ideas! Register at go.osu.edu/soilhealth2022. Recordings of previous webinars are available at https://agcrops.osu.edu/events/webinar-recordings/dirt-soil-health-investing-below-surface-0
Test Drive New Organic Seed Varieties
Are you a farmer or gardener in the Upper Midwest? Are you interested in contributing to the development of new tomato and pepper varieties for organic farmers in our region? Consider joining the Seed to Kitchen Collaborative and SeedLinked plant breeding network. Read more at https://seedtokitchen.horticulture.wisc.edu/
Warner grant proposals for Sustainable Agriculture Research – due March 1
The OSU Sustainable Agriculture Team and Agroecosystems Management Program (AMP) is accepting proposals for on-farm research projects on sustainable agriculture topics. Research is intended to identify and publicize sustainable agricultural practices and systems that are profitable, socially responsible, energy efficient, and improve water quality and other environmental concerns relevant to Ohio farmers. Farmers are invited to partner with OSU scientists and extension educators to carry out these on-farm projects. Read the Request for Proposals at go.osu.edu/2022-warner-grants or contact Doug Jackson-Smith if you have questions. Proposals are due March 1, 2022.
Organic Grain Training
The Organic Agronomy Training Service (OATS), the University of Wisconsin-Madison’s OGRAIN, and the American Society of Agronomy (ASA) have launched a video series, call series, and listserv for organic advisors and ag professionals to connect and learn from each other. Read more at https://www.organicagronomy.org/organic-advisor-call-series.
The OFFER program cooperates with Ohio State Agricultural Operations to maintain organic production space for field research. Most of the land is located at the West Badger Farm in Wooster and is managed organically when not active in research projects. Facilities include dedicated organic equipment, grain storage, and staff to assist with farm and certification management. Researchers or cooperators interested in reserving organic research land or cooperating for trials or demonstrations should contact Brian Gwin, OFFER coordinator. Multiple small and large grants are available for this work. Find more resources around this topic at https://offer.osu.edu/resources/resources-researchers.
This summer, West Badger is home to organic variety trials for corn and oats, year 2 of a perennial wheatgrass trial, and cultivation equipment trials in partnership with Tilmor. Plans for additional variety trials are underway.
|Cultivation Equipment Trials|
OFFER is pleased to partner with Tilmor for equipment trials on our West Badger research station. Based in Orrville, Ohio, Tilmor specializes in affordable tools and equipment for smaller farms. Read more about Tilmor at tilmor.com/en-us
|Organic Variety Trials|
Oats were planted in early spring along with organic corn variety trials.
|Variety trial results are archived at u.osu.edu/perf/. Results from 2021 oats should be added soon.|
|Perennial Wheatgrass Trials|
Kernza seed and forage was harvested in late July at the Wooster (above) and Fremont (below) sites. Kernza is a potential dual purpose crop for grain and forage. This work is part of a multistate project to track productivity, quality, and soil health under various fertilization and harvest timing treatments
|Weed pressure remains high at the Wooster site, but the Fremont trial was virtually weed free this second year. Leader researcher Steve Culman will continue to monitor this potential crop's competition with weeds to see if this crop might be useful duing organic transition or as an effective weed management tool with soil health benefits.|
Ohio State soil researchers Steve Culman and Christine Sprunger have analyzed soil health and management data from around 900 Ohio farm soil samples. The samples were collected during various on-farm research projects in the last few years, including about 200 from organic operations.
The Culman and Sprunger labs have looked for relationships between soil health metrics and the corresponding soil type, sampling depth, and management practices. Below are a few quick highlights and opportunities to learn more.
Management Impacts on Soil Health
The study suggests that the most effective way to increase microbial activity and other soil health indicators was to include perennials in the crop rotation, especially for multiple years.
Organic growers will be happy to hear that, so far, cover crops appear to be a better soil health building strategy than no-till. That’s not to say that tillage is good for soil health. More complex crop rotations and increased tillage showed a negative effect on organic matter and microbial activity.
Culman cautions that this is “noisy” data based on observation, not a side-by-side controlled study, nor is it a comprehensive sampling of soils. More work is definitely needed. Some of this future work will look at aggregate stability (a measure of soil physical health), compare the soil health impact from different types of tillage, and compare organic vs. conventional practices (for example, the effect of organic vs. synthetic fertilizers). The researchers are also interested in ways to decrease tillage passes in an organic system.
Emerging Tests for Soil Health
As farmers and consumers focus increasingly on soil health, there is a growing need for better soil health measurements. Data from these on-farm soil surveys is helping to further this goal as well.
Standard soil tests include a total organic content measure, but most organic matter in the soil is not available to plants. Recent research also suggests that total organic matter changes very slowly over time and is probably not the best tool if you want to track how new management practices are impacting soil health.
Ohio State’s soil labs have been evaluating soil health tests for accuracy, for their value in management decision-making, and for cost and turn-around time. The goal is to recommend useful tests to commercial labs so that these can be offered directly to farmers, along with information about state averages, ranges, and how the test values vary with soil type.
It's important that organically managed soils continue to be part of this sampling project. Ohio State will collect soil samples again in 2021 as part of eFields – an agronomic crops program to conduct and share on-farm research. Contact your local extension educator or email email@example.com for more details on getting your soil sampled for this statewide study. Individual soil test results will be shared with participating growers.
- Management Practices That Impact Soil Health and Organic Matter
March 17 Sprunger presentation (45 minutes) - part of Ohio State's 2021 Winter Organic Webinar Series
- Using Research and Data to Improve Soil Health
February 25 presentation, Steve Culman & Elizabeth Hawkins - part of Ohio State's 2021 Soil Health Webinar Series
- eFields report 2020 - see page 224 for Soil Health Survey report.
- eFields program
As many producers look to diversify their farms and find opportunities to increase on-farm revenues, one potential avenue to consider is organic grain production. A Transition to Organic Grains workshop offered through Ohio State University Extension in Putnam County will take place in Ottawa, Ohio, at the Putnam County Educational Services Center on March 30, 2021 from 9 am to 2 pm.
The workshop is designed to answer producers’ common questions when considering a move from conventional to organic production. What do I need to know and what steps do I need to take to transition my fields to organic production? How long will the process take? What markets are available for my grain? How do I approach fertilization, weed management, and pest control? These and many more questions will be answered by industry and extension experts – as well as first-hand experiences of organic farmers.
The Transition to Organic Grains workshop is offered at no cost, but registration is required. Registration includes all handouts and a boxed lunch. To register, please call the Putnam County Extension office at 419-523-6294, register online, or email Scheckelhoff.firstname.lastname@example.org.
Thanks to Beth Scheckelhoff for penning and sharing this article (originally published in the C.O.R.N. Newsletter).
Learn more about the perennial grain kernza and see the trial plot in this brief video: https://youtu.be/epJaE5ihiVE (3:17)
Only a few days are left to reserve your spot at Ohio’s largest sustainable food and farming conference. Registration ends on Monday, February 8 for the Ohio Ecological Food and Farm Association’s 42nd annual conference, which will be held online February 10-15.
Among the speakers from Ohio State this year, extension soil specialist Steve Culman will be sharing information on his USDA perennial grain trials. This is Culman’s second research project on the perennial wheatgrass known as kernza. He is testing an organic variety of kernza for suitability in Ohio as a dual-purpose crop (forage and grain production). This summer his lab will begin on-farm trials and is looking for additional participants.
Kernza is used mainly for forage and grazing in the western U.S. While the grain has end uses and nutritional values similar to wheat, Culman admits the grain production is not very good and that markets and facilities for kernza are only just developing. While it has potential for dual purpose production, more research and development will be needed.
So why would a farmer consider kernza? Because it has a third purpose of great importance: Soil health.
“Organic systems go through this dichotomous cycle of growing cash crops, and then growing a crop for conservation or soil development," Culman notes. "With kernza you could do both.”
Recent Ohio State research reviewed hundreds of regional soil tests results, comparing management practices with various soil health measurements linked to yield, biological activity, and fertilizer efficiency. The most effective management practice for improving soil health was the use of perennials. Perennial crops reduce traffic and tillage, but they also leave roots in the ground year-round to contribute to biological activity, provide below-ground biomass, and crowd out weed growth. Kernza really shines in root development, with roots that reach 10 feet down or deeper and spread horizontally to outcompete weeds.
“Kernza stays pretty green through harvest,” says Culman. “It’s not like wheat. You harvest the grain in late July/early August. So you could harvest the grain, then chop or hay the remaining biomass. Then you can let it regrow. This is not enough time to develop seed heads, but the regrowth should get knee high or so in the fall. Then it can be grazed."
Based on his previous trials, Culman feels kernza has great potential for organic transition, weed control, riparian zones, forage, fall grazing, and even grain production, all while improving soil quality.
The OEFFA conference kernza presentation will be Friday, February 12 at 10 a.m., but conference attendees will also be able to watch recorded presentations through March. Dr. Culman will also be available in the OFFER virtual conference booth on Friday, February 12 from 2-3 p.m. for anyone who would like to know more about the on-farm kernza trials or to chat about soil health and fertility.
See the full line up of OFFER booth events at offer.osu.edu/booth. We will also host Glen Arnold, extension field specialist in manure management; Erin Silva from University of Wisconsin and OGRAIN; and Rich Minyo, organic corn variety trial researcher.
For more information on the OEFFA conference, visit https://conference.oeffa.org/.
To learn more about the soil health and management study findings, join us for "Management Practices That Impact Soil Health and Organic Matter with Christine Sprunger, March 17 at 11 a.m., part of the OFFER 2021 Organic Winter Webinar series.
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.