Recent Blog Posts
written by Andrea Leiva Soto, Horticulture and Crop Science
Ohio State researchers compared an organic system to a conventional one, looking at several soil quality indicators such as bulk density, organic matter content, and nematode populations. After four years, the organic system had fewer harmful nematodes, especially during the hay phase of the rotation. Mineral nitrogen was more abundant in the conventional system, while microbial nitrogen prevailed in the organic system. Soil bulk density did not differ between systems, even though intensive tillage was done in the organically managed fields. However, despite the high carbon inputs added to the organic system, organic matter was only slightly higher compared to the conventional system.
Nematodes have a bad reputation for damaging crops and garden plants, but some can be quite important for plant growth. Certain kinds of nematodes eat bacteria and fungi that cause plant diseases. Others decompose organic matter, providing plant nutrients. Studies indicate that nematodes supply 27% of the soil nitrogen that is available to plants. Today, nematodes are increasingly used as an indicator of the status of the soil food web. The soil food web is a complex network with organisms that provide services to the farm ecosystem like regulating pests, nutrient recycling, modifying soil structure, or even breaking down man-made chemicals.
Organic matter additions have been shown to influence nematode populations. Adding green manure cover crops or decomposed animal waste can decrease root-feeding nematodes. Additionally, organic amendments are known to increase soil nitrogen, organic matter and microbial biomass, and reduce soil bulk density, leading to less soil compaction. As a result, roots explore deeper and have more oxygen available leading to more vigorous growth.
However, the intensive tillage practices used to incorporate amendments or control weeds, disrupt the soil ecosystem, affecting the populations of beneficial microbes and nematodes. Synthetic fertilizers, insecticides, and soil compaction can also cause similar undesirable effects.
To better understand these kinds of interactions and develop insights into how best to manage them, a study at the Ohio Agricultural Research and Development Center (OARDC) in Wooster, Ohio, compared conventional and organic farming systems and how soil characteristics, nitrogen cycling, and nematode populations are affected by each system.
The conventional system used chemical fertilizers, herbicides, and reduced tillage in a corn–soybean rotation. The organic system incorporated fresh straw, beef manure, poultry compost, and intensive tillage in a corn–oat–hay rotation. Soil samples were taken in the spring before soil inputs, and in autumn after crop harvest. Samples were taken from between and within the crop rows. Then for each sample, the nematodes were counted and identified, and soil bulk density, organic matter, and nitrogen were measured.
Results: After four years, the organic system had fewer harmful nematodes, especially for the hay phase of the rotation. Mineral nitrogen was more abundant in the conventional system, while microbial nitrogen prevailed in the organic system. Soil bulk density did not differ between systems, even though intensive tillage was done in the organically managed fields. And despite the high carbon inputs added to the organic system, organic matter was only slightly higher compared to the conventional system.
Take Home Messages
- When you are transitioning to organic, it is important to reduce synthetic inputs gradually. The soil system needs time to build different sources of nutrients to be sustainable in the long-term. It is known that after the transition period, organic farms have more nitrogen in the soil compared to conventional farms, mainly due to a build-up of the microbial nitrogen pool, but these benefits will not be available immediately.
- Organic amendments and crop rotations can decrease harmful root-feeding nematodes in the soil. And by including hay in the rotation cycle, you can decrease these nematode populations even more.
- Intensive tillage can reduce the soil-related benefits of organic farming. On the other hand, organic inputs should significantly increase soil organic matter and decrease soil bulk density. In the organic farming system discussed above, the benefits of the large organic inputs were diminished by the intensive tillage routine. Rather than seeing a decrease in compaction level, the soil bulk density remained the same. And there was only a minor boost in soil organic matter. Decreased use of tillage in organic farming would better take advantage of the benefits that an organic system can provide.
Read more about it:
This study was conducted at Ohio State in the early 2000s. Published results are availabe online.
Briar, Shabeg S.; Grewal, Parwinder S.; Somasekhar, Nethi; Stinner, D.; Miller, Sally A. 2007. Soil nematode community, organic matter, microbial biomass and nitrogen dynamics in field plots transitioning from conventional to organic management. Applied Soil Ecology 37: 256-266.
Read more news and information on organic agriculture research at offer.osu.edu.
The Ohio State Soil Balancing Team is concluding a five-year project examining the beliefs, practices, and effects of soil balancing. Soil balancing involves the use of high calcium amendments to manipulate the ratio of calcium, magnesium, and potassium in the soil. For decades, proponents have claimed that the right balance of these cation nutrients will improve field conditions and yields, but none of these effects have been replicated by modern university research.
Through interviews, surveys, and literature reviews, the team gained a better understanding of why and how soil balancing is used by farmers and how it had been studied by researchers. The group found that while most researchers and university educators viewed soil balancing as an ineffective fertilization program; farmers and consultants who use soil balancing view it as a holistic method for improving soil health.
With input from a farmer advisory committee, the team designed long-term field experiments situated on organic farms and university research sites. The field trials found some evidence that changes in Ca:Mg ratios were associated with changes in soil structure and weed populations. However, the team was unable to document consistent effects on these characteristics, or on soil biology, crop quality, or yield.
Based on the overall project findings, the Ohio State team recommends further investigation of how soil balancing’s effectiveness is impacted by specific site conditions such as cation exchange capacity (CEC), clay content, or management practices. Meanwhile, the team has issued the following recommendations for anyone using or considering soil balancing.
Soil test data is critical to making informed decisions about managing Ca:Mg ratios.
Watch your pH if using lime. Gypsum is a better choice to change your Ca saturation ratio without affecting pH, and it also provides sulfur.
Soils with a CEC below 10 meq/100 g may develop K deficiencies. In soils with a low holding capacity for cations, excess Ca can quickly lead to deficiencies of K, and possibly Mg. We did observe this in on-farm sites.
Consider economic factors. On soils with higher CEC, more time and amendments will be needed to increase the Ca:Mg ratio. Depending on the amount of change needed and the value of your crop, using soil balancing may be cost prohibitive.
Any time you try a new practice, monitor the results. If possible, try using the new practice on only part of your farm and compare it with a similarly managed area to see if the new technique is making a positive contribution over time.
Additional Resources and Information are available at https://offer.osu.edu/soil-balancing/resource including summary reports, articles, and presentations.
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.
Organic farms are excellent hosts for pollinators because of the reduced danger of pesticides, but also because of the greater diversity that organic operations often support, says Ohio State Bee lab director Denise Ellsworth. With over 450 different species of bees in Ohio, a variety of plants and habitats is important.
Ohio State’s Bee Lab is dedicated to research and outreach on topics related to honey bees, wild bees, and other pollinators. Ellsworth has partnered with others to develop numerous factsheets and resources on Ohio-specific bee and pollinator topics, including id guides to common Ohio bees, and tips for creating pollinator habitats with specific tree and plant suggestions.
Honey bees can of course serve as an additional source of income. Honey production comes to mind immediately, but some farmers also manage pollinator services, renting out their hives to various fields during the growing season. For those not looking to raise bees commercially, there are still benefits to creating pollinator habitats. According to Ellsworth, pollinators share the same habitat needs as other beneficial insects. “So even if you’re not growing something that relies on pollinators, you’ll be creating a habitat for other beneficial insects: wasps, lady beetles, and other ‘good guys,’” she says.
Whether you’re managing a small personal garden or a multi-acre farm, areas to develop for pollinator habitat are easy to identify: Fallow fields, cover crops, hedgerows, windbreaks, riparian buffers, ponds and ditches, natural or undeveloped areas, pastures, and flower gardens can all be improved with features and plants to attract pollinators.
Selected Ohio State resources are listed below. You can also visit the Ohio State Bee Lab website for more resources including current research, and information on the Ohio Bee Atlas, to which citizen scientists can contribute photos and observations. Additional resources are available through the Xerces Society for Invertebrate Conservation. They have several general factsheets and guides related to organic farms and pollinators. https://xerces.org/pollinator-conservation/organic-farms/
Honey Bee Resources
Getting Started with Honey Bees, IPM for Bees, etc.
Creating Pollinator Habitat
presentations from 2019 OEFFA Conference and 2019 Grazing Conference
Attracting Pollinators to the Garden
Bee, Wasp, Hornet, and Yellow Jacket Stings for Trainers and Supervisors
Bumble Bees in Ohio: Natural History and Identification of Common Species
How to Identify and Enhance Ohio’s Wild Bees in Your Landscape
Ohio Bee Identification Guide
Ohio Bee Identification Cards and Posters
Ohio Trees for Bees
Pollinator Quick Guide: What You Can Do to Help Bumble Bees
Pollinator Quick Guide: What You Can Do to Help Honey Bees
Pollinator Quick Guide: What You Can Do to Help Native Bees
Pollinator Quick Guide: What You Can Do to Help Pollinators
Honey Bees in House Walls
Based on an article from Organic Seed Alliance by Kiki Hubbard. Read the full article here.
New varieties of disease-resistant cucurbits are commercially available as a result of Cornell University's Eastern Sustainable Organic Cucurbit Project.
Through participatory efforts with farmers and regional seed companies, Extension researchers developed new varieties with organic producers in mind, focusing on resistance to common diseases and pests, but also on production and culinary characteristics important to organic farmers.
“All of our successes with DMR are owed to farmer input,” says project director Michael Mazourek. “We took moderately resistant material that we had at Cornell, moderately resistant material identified by organic farmers, and people are seeing the literal cross-pollination of these partnerships in DMR varieties now available to growers.”
‘Trifecta’ muskmelon stood out for its excellent eating quality and yield–even under levels of downy mildew pressure that defoliated most commercial melon varieties. The variety also exhibited good bacterial wilt resistance and was less prone to damage from striped cucumber beetles. ‘Trifecta’ is currently available for sale through Common Wealth Seed Growers and Southern Exposure Seed Exchange.
DMR401 cucumber, a downy-mildew resistant (DMR) slicing cucumber variety, now available for purchase through Common Wealth Seed Growers, High Mowing Organic Seeds, SeedWise, and Southern Exposure Seed Exchange.
DMR264 cucumber, excellent resistance to new strain of downy mildew, smaller and bred for warmer climates with severe pressure from downy mildew. Available from Common Wealth Seed Growers.
Additional varieties are being tested for release.
The Eastern Sustainable Organic Cucurbit Project has received funding from the USDA Organic Research and Extension Initiative, as well as the Organic Farming Research Foundation, Sustainable Agriculture Research and Education (SARE), and the Clif Bar Family Foundation. Read more about the project at eOrganic.
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
Written by Evin Bachelor, Law Fellow, Agricultural and Resource Law Program
The Ohio Specialty Crop Registry connects producers of specialty crops, beekeepers, and pesticide applicators to one another through free online registries. Producers of specialty crops and beekeepers may voluntarily report the boundaries of their specialty crops and beehives. The registry then compiles this information in a mapping tool that also provides the contact information of the registrant. In doing so, pesticide applicators are better able to avoid these areas and minimize spray drift.
The Old System: the Ohio Sensitive Crop Registry
The Ohio Department of Agriculture (ODA) first launched a registry for sensitive crops in 2014 so that pesticide applicators could know the locations of sensitive crops before spraying in a given area. The registry came about at a time when widespread demand for organic foods required more farmers to closely monitor what came into contact with their crops. The original tool allowed commercial producers of at least a half-acre of a single type of sensitive crop to register. Sensitive crops included just about any non-row crop such as fruits, vegetables, and herbs. Apiaries, outdoor aquaculture, brambles, certified organic farms, nurseries, greenhouses, and orchards also could be registered.
The New System: the Ohio Specialty Crop Registry
Now, ODA partners with FieldWatch, Inc. to operate the Ohio Specialty Crop Registry. FieldWatch, Inc. is a non-profit organization that operates three registries: DriftWatch for producers of specialty crops, BeeCheck for beekeepers, and CropCheck for producers of row crops. FieldWatch creates maps based on the information from these registries, and makes those maps available to pesticide applicators in another program called FieldCheck. In summary, the three registries are for the producers and beekeepers, and FieldCheck is for the pesticide applicators.
Ohio currently only uses the DriftWatch and BeeCheck registries. According to ODA, the list of sensitive crops under the old program is virtually the same under the new system, meaning that producers of any non-row crop may utilize DriftWatch. While beekeepers may report the location of their beehives in DriftWatch, ODA recommends that beekeepers with no specialty crops use BeeCheck.
FieldWatch, Inc. continues to update its tools to add features and indicators, and CropCheck represents one such development. New for 2019, this registry allows producers of row crops like corn, soybeans, and wheat to register their crops. Its development comes on the heels of the introduction of dicamba-tolerant seeds. Only Arkansas, North Carolina, Illinois, and Indiana have adopted CropCheck for 2019. Ohio has not yet adopted it.
Connecting the Dots between the Registry and Liability
At this point you may be asking yourself, why is this in the ag law blog? That’s a fair question, and the answer is simple: risk management. As more farmers adopt organic practices, as pesticides and seeds change, and as weather patterns evolve, the risk increases that pesticide drift may come into contact with and negatively impact specialty crops and beehives.
The law expects people to act reasonably and to exercise due care at all times, and this default duty applies to pesticide applicators. Common claims for drift include negligence, nuisance, and trespass. Each of these claims examine whether the parties acted reasonably and with due care. Most often, when a court decides that a pesticide applicator acted unreasonably, it is because he or she failed to apply the pesticide in a manner consistent with the label. Following the label is certainly an expectation, but it is not the only thing a court will consider.
When a pesticide applicator does not use FieldCheck, a perceptive attorney representing beekeepers and producers of specialty crops would likely argue that the use of FieldCheck is an industry standard. If an attorney could establish this, then the failure to use FieldCheck would mean that a pesticide applicator failed to act in a reasonable manner and exercise due care. While we have not seen an Ohio court consider this issue yet, as use of the program continues to grow, this argument will come to hold more weight when a case does arise.
When a pesticide applicator does use FieldCheck, he or she has a stronger argument that he or she acted in a reasonable manner. FieldCheck provides pesticide applicators with a way to know exactly where registered sensitive crops and beehives are located, and allows the applicator to buffer accordingly. FieldCheck provides a quick, cheap, and easy way to manage legal risk, alongside following the label. Applicators who use the program may want to document when they used the program and also how the maps impacted their application plan.
These scenarios presume that the beekeeper or producer of specialty crops has registered the locations of their bees or crop with a FieldWatch registry. When sued by a beekeeper or producer of specialty crops who did not register their locations, a pesticide applicator could use similar arguments as noted above in order to defend against the lawsuit. However, the applicator’s focus would likely regard the lack of notice. Again, these arguments alone would not likely determine the outcome of the case, but they would help the court determine whether the parties acted reasonably.
What about hemp?
Another question that some of our readers will also be asking is: which registry is for hemp? We made a call and left a message with FieldWatch. If or when hemp production becomes legal in Ohio, we’ll be sure to provide an update on which registry is proper for hemp. Ohio’s hemp bill is on the move, and the Ohio Senate Agriculture & Natural Resources Committee completed its third hearing of the bill this week. However, we can’t forget that growing hemp is not legal in Ohio unless and until the bill is passed into law and the regulatory system is created.
Reprinted by permission from the Ohio Agricultural Law Blog. The blog is a service of the Ohio State Farm Office, which provides information for agricultural producers and land owners on agricultural law, taxation, production economics and farm management.
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.
Use of compost and a mixed species hay crop are recommended.
For farmers transitioning from a conventional to an organic farming system, decisions made during the three-year transition period can influence important factors of future production, such as soil-borne pathogens, soil fertility, and soil structure. In this study, compost incorporation strongly affected physical, chemical, and biological soil health factors and, overall, the soil food web. Using a mix of perennial hay during the transition was most successful in reducing disease-causing pathogens in the soil. Highest available N and yields occurred in the plots using high tunnel vegetable production.
Materials and Methods
A three-year study was conducted in Wooster, Ohio, to evaluate four common rotational strategies used during transition from a conventional to an organic farming system. The four organic transition strategies evaluated were: 1) tilled fallow, 2) a single planting of mixed species perennial hay, 3) low intensity open field vegetable production, and 4) intensive vegetable production under a high tunnel.
Each transition strategy plot was split in half with 15,000 lbs./ac composted manure applied each year to one half.
At the year of certification, the fields were planted to tomato, with two smaller plots of soybean.
- Compost treatment increased organic matter of soils in all treatments, lowered bulk density, and increased NO3-N, and microbial biomass-N.
- The addition of compost boosted plant vigor for tomatoes for all transition strategies, but had an inconsistent effect on suppression of soil-borne diseases.
- Transition cropping strategy was the main factor influencing bacterial community structure in the soil and the rhizosphere.
- Bacterial communities involved in disease suppression were more abundant in soil previously cropped with hay compared to tilled fallow and low-intensity vegetable production. This was true for both tomato and soybean crops.
- Overall, the mixed hay was the most effective in decreasing damping-off for both tomato and soybean crops.
- Tomato yield during year four was much higher in the high tunnel plot. The hay treatment also showed better yield than the tilled fallow and open field vegetable production.
Why Researchers Think the Hay and High Tunnel Treatments Did Better
Disease suppression might happen in two ways. One involves specific action against pathogen populations. For example, brassicas (cauliflower, kale, turnip, radish, cabbage) suppress soil-borne diseases by exuding sulfur-rich substances that are toxic to many pathogenic soil organisms. And certain species of nematodes eat bacteria and fungi that cause plant diseases. Disease suppression can also occur from high competition for available resources. In both cases, the disease suppression is associated with the overall composition of the microbial community (bacteria, fungi) present in the soil and the rhizosphere.
The hay crop used in this experiment was a combination of Festulolium (a rye fescue hybrid) under-sown with alfalfa, red and white clover, timothy, chicory, orchardgrass, and plantain in equal proportions. Researchers concluded that the above-ground diversity of the hay mix supported an increase in beneficial soil organisms that compete or interfere with pathogens, thus, reducing incidence of disease in future crops.
The highest yields in this study were from the high tunnel plots. While some of the increase resulted from extending the growing season, soil analyses also found a higher level of available N in the high tunnel plots. Researchers think this was a result of maintaining the soil food web in a biologically-active state during the cold early spring months in northern Ohio. The monthly mean soil temperature inside the high tunnels was warmer by 35–41°C from January to May while from July to September it was marginally lower than the outside soil temperature. (Based on top 4 inches.)
For more information on using tunnels in vegetable production, visit the Vegetable Production Systems Laboratory’s Crop Enivronments page.
Prepared by Louceline Fleuridor and Cassandra Brown
Based on summaries of the following papers:
Benítez, MS; Baysal, F.; Rotenberg, D.; Kleinhenz, M.D.; Cardina, J.; Stinner, D.; Miller, S.A.; Gardner, B. B. 2007. Multiple statistical approaches of community fingerprint data reveal bacterial populations associated with general disease suppression arising from the application of different organic field management strategies. Soil Biology and Biochemistry Volume 39, Issue 9, September 2007, Pages 2289-2301
Briar, S.S., Miller, S.A., Stinner, D., Kleinhenz, M.D., & Grewal, P.S. 2011. Effect of different organic transition strategies for peri-urban vegetable production on soil properties, nematode community, and tomato yield. Applied Soil Ecology, 47, pgs 84-91.
Baysal, F; Benitez, MS; Kleinhenz, MD; Miller S.A.; Gardner B.B. 2008. Field management effects on damping-off and early season vigor of crops in a transitional organic cropping system. Phytopathology, Vol. 98, No. 5.
"Soil balancing is complex, it's prevalent, and it's shown the capacity to endure. It also raises very interesting, and sometimes difficult to answer, questions. All of those are reason enough for us to chat, but as we address those questions we’re also very likely to learn about soils, about crops, about farms and farmers, and the people who advise farmers and supply them."
- Matt Kleinhenz, Ohio State, vegetable production specialist
Below are a few notes and quotes from our first two Soil Balancing call-in conversation. Recordings of both calls are available at our website, go.osu.edu/SB-call-in, where you can also find details about our final call-in event on December 12, 2018, 1:30-3:00 p.m. eastern time.
What We Think Soil Balancing Does
“The physical and biological aspects of the soil have more impact on an ultimate yield than actual N, P, and K does. So we're in working with these heavier clay soils. Our main goal is to minimize stress and duration of stress on the crop, so we're trying to preserve yield, because we continually stress this crop and most of the stress on those clay soils comes from water.“
- Joe Nestor, Nestor Ag, LLC (November call-in)
Joe Nestor works as an independent crop consultant in Ohio, Michigan, Indiana. He estimates about 70% of the soils he works with are heavy clay. His main goal using soil balancing is to improve water infiltration for less stress on crops.
“As we reduce flooding in the fields, we end up with a healthier crop in many cases -- a crop that survives, versus a crop that dies out under flooding conditions, and as a result, fewer weeds. When the crop dies or when the crop is not vigorous what grows in those in those areas of the field are weeds primarily. And we've all seen those dead areas in the field that come up in foxtail and other weeds.”
- Doug Doohan, Ohio State, weed specialist (October call-in)
Doug Doohan theorizes that soil balancing might affect weed populations indirectly through improved soil structure and infiltration. He cautions that there is no hard data on this yet, but it’s a research question be is studying based on conversations with farmers.
What Soils Does SB Work Best On?
“I think guys that have promoted the Albrecht balance have kind of given people the idea it works in any soil and that's really not the case. And so I think some of that has drifted into the research facilities in thinking that it works in all situations and that's not the case.”
- Bill McKibben, consultant, Soil Tech, Inc. (October call-in)
Although McKibben says he grew up as an “Albrecht guy,” i.e., focused on the 65% Ca, 15% Mg base saturation recommendations, his experience has shown him this technique is much more effective on clay soils.
However, by growing and incorporating a mixed species cover crop into his soils, vegetable grower Bob Jones reports significantly increasing the CEC on his sandy loam soils. He also uses compost teas and mineral applications, rotating fields in and out of production. He feels this increase of organic matter combined with increasing his Ca:Mg ratio has led to improvements in soil and crops.
“We're raising the CEC, we're raising the organic matter levels, we're getting the calcium up in that seventy to seventy-five percent ratio with magnesium in line with that of 7:1 and that seems to be— We seem to be seeing a very marked improvement in the quality and the shelf life of the product that we're growing.”
- Bob Jones, The Chef's Garden (November call-in)
Focus on the Crop, not Just the Numbers
“The number one goal, the number one objective, needs to be to grow a really healthy crop…. So in terms of priorities sometimes the lab report might indicate that we have a soil that is severely out of alignment and we need to make major adjustments, but the budget doesn't exist and it's not possible to make that happen. In those cases, the priority always needs to be to grow a really healthy crop first and then fix the soil over time as we're able to.”
- John Kempf, consultant, Advancing EcoAgriculture (October call-in)
Other consultants chimed in, saying it’s important to get out in the field and see what’s happening. Both Kempf and McKibben recommended a Paste Analysis test to examine how nutrients are moving into the soil solution and becoming available to plants.
"I can only say what works on our farm. Going back to the question of the truth, what's the truth on your farm? Then go with that. And you can only do that by experience. My father told me a long time ago that the best fertilizer you can put on a field comes from the soles of your feet and that means walking through the field and seeing what's going on and listening to the plant. The plant’s the best test mechanism we have. Does the plant look healthy?"
- Bob Jones, The Chef's Garden (November call-in)
On-Farm Experience vs. Research
“If the universities have a different opinion than the farmers, I normally go with the farmer opinion. They may not know why something is working, but they do know that it does work. And maybe the researchers…. they may not have the whole system, where a farmer would.”
- Will Glazik, organic farmer, Cow Creek Organic Farm
Glazik spoke in detail about how he applied soil balancing on his fifth-generation family farm: how his inputs changed over time and what improvements he saw. He looks to researchers to answer questions about ‘why’ something works, which helps him replicate a practice at his own farm.
“Scientists, I think, legitimately, have a healthy skepticism about what they might consider anecdotal reports of things that people say, especially when it comes…with the sales interest in mind, and they want us to validate that. On the other hand, farmers have a very healthy skepticism and legitimate skepticism of science, and the degree to which scientists’ work is directly as applicable or useful in their work, and that's why they turn to farmers often and legitimately to get advice and counsel.”
- Doug Jackson-Smith, Ohio State, natural resources and rural sociology specialist
Doug Jackson-Smith says that if soil balancing is to move forward, farmers and scientists must work together and bring the on-farm experience to science, and science to the on-farm experience.
Why Aren’t More Universities Studying Soil Balancing?
Steve Culman said many scientists feel this topic has already been decided. But his review of published literature and farmer input, made him think there was more to study. Other panelists theorized that Soil Balancing was an unpopular topic for study because there were few products (and sales revenues) tied to it or because previous research was done on soils poorly suited for the technique.
“I think that the beauty of science is that we… claim to be a self-correcting enterprise. It might take a year or two, it might take ten years, it might take decades. We believe that truth is the foundational thing that we're after, and that, if we have it wrong now, that in time and with additional evidence, we're going to change the way we think about things.”
- Steve Culman, Ohio State, soil fertility specialist (October call-in)
"You're asking, should we be doing more research and generating more numbers. I think so in this regard, because it is a question that I get at almost every soils talk I give. Can I improve my drainage by increasing the calcium-magnesium ratio?"
- Josh McGrath, University of Kentucky (November call-in)
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