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.
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
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.
Biostimulants are not exclusive to organic systems, but they are a common input for organic growers. Ohio State vegetable production specialist Matt Kleinhenz has spent many years studying microbial-based biostimulants (MBBS). Few agricultural input markets have seen the kind of explosive growth that has occurred with MBBS.
“These products are widely available, relatively inexpensive, are said to offer interesting and appealing benefits, and rarely put users at significant risk, unlike some other products,” says Kleinhenz.
Nicole Wright, program coordinator for the Vegetable Production Lab’s MBBS project, also attributes market growth to increased interest in microbiology.
“I think growers are applying them and thinking about soil and soil microbiology,” she says, “They are thinking ‘everything I hear says that having healthy soil means having lots of living things in them and if I can contribute to that, it’s a good thing.’”
With a constant stream of products entering and exiting the market, Kleinhenz and his team are less interested in testing specific products and more interested in answering the bigger questions surrounding this subset of agricultural inputs. Their research has focused on identifying which factors are important to product efficacy, such as the effect of timing and application rate.
Kleinhenz and Wright have this advice for growers interested in or already using MBBSs on their crops:
- Do background research. Just because a product is OMRI-listed does not mean it’s been found effective. Set aside time to read up on the product. Take a critical look at label instructions. What details are provided about the timing, application rate and application methods? What can the manufacturer tell you about mixing it with other products or using it in specific conditions or crops?
- Be wary of claims that seem exaggerated. Most of these products create modest, gradual, and/or inconsistent yield improvements. Growers should have realistic expectations for MBBS products.
- Product consistency can be an issue with MBBSs. If a product only works some of the time, the cause may be related to the user, the manufacturing process and product itself, or production conditions. For example, environmental factors like soil fertility, pH, or cropping history might influence the product’s effectiveness.
- Use storage and handling procedures that acknowledge these are living products. Avoid temperature extremes and chlorinated water, for example.
- Track what happens. Referrals from other users of the product are valuable. But remember that their success won’t necessarily be repeated in your farm’s unique conditions. When trying a new product or practice, maintain a similar untreated part of your field to compare. Do your own experiments with rate and timing. Keep records on what you applied, where, and take notes on any differences you see in growth, yield, quality, etc.
- Use good cultural processes to increase microbials in your soil too. Wright likens MBBS products to taking a vitamin vs. eating healthy foods. Cultural practices that favor soil biodiversity, organic matter, and good drainage are also needed to provide food and conditions that allow microbial life to thrive.
Change is coming
So far, these products are largely unregulated. For the first time, the current farm bill includes language defining a biostimulant--an important first step in creating better uniformity in the industry, says Kleinhenz. Some manufacturers are concerned about the overall image of MBBS products and are pushing for a more narrow definition along with efficacy testing.
Kleinhenz feels regulation will usher in increased product consistency and better information for consumers, but regulation may also limit the number of products available. Testing product efficacy requires time, expertise, and/or expenses that smaller manufacturers may find challenging.
He also questions if it is truly appropriate to apply the same efficacy standards used for many mainstream agricultural inputs. Based on averages and standard, proven statistical analysis, a comparison of treated and non-treated plots failed to show that inoculation (product use) significantly influenced yield. However, the Vegetable Production Systems Lab team observed many times when a MBBS did increase yield (and a few times when it lowered it).
“If you went out to your truck and it only started half of the mornings, you’d be pretty annoyed and conclude it’s unreliable, that it’s not working,” Kleinhenz says. “However, if you apply a product to your crops or soils and see measurable improvement say, 30% of the time, you might still find the application worthwhile if the costs and other risks were low. Our goal as a team is to provide growers and others with information they can use to distinguish worthwhile from unwise investments and practices.”
There are many additional practical questions to answer that could involve microbiology and decision-making. For now, Kleinhenz and his lab are enjoying the conversation and questions stimulated by this growing and changing industry.
This research is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Organic Transitions Program under award Number 2016-51106-25714 and also under award number 2016-38640-25381 through the North Central Region SARE program under subaward number LNC16-380.
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.
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
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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