Research newly Completed and Started

High tunnel studies are affected by weather. However, typically, high tunnel work continues when some operations in open field production are halted. Like growers, the Vegetable Production Systems Lab (VPSL is transitioning to full “summer mode” as conditions allow. See the six panels below for snapshots of a portion of our recent and near-term activities and don’t hesitate to contact us for more information or if we can assist another way.

Matt Kleinhenz (kleinhenz.1@osu.edu; 330.263.3810)

Five-year soil balancing project results

Another wet spring, and many farmers postpone field work awaiting drier conditions. Could improved drainage be obtained through the application of common gypsum? This is one of the claims made by many consultants and farmers who use a practice called soil balancing.

Ohio State’s five-year study on soil balancing has been mentioned in previous VegNet articles. The project involved multiple long-term field tests, as well as interviews and surveys to better document practices and beliefs surrounding soil balancing. Despite a lack of past research proving soil balancing’s effectiveness, we found that the practice is used heavily by organic and conventional farmers in our region to reduce weeds, and improve soil quality, crop quality, and yields. While we were unable to demonstrate improvements in crop yields or quality, we did see limited effects on soil quality and weed populations in some of our test sites during the final year of the study.

Defining Soil Balancing

Traditionally, soil balancing strives to keep base cations calcium (Ca), magnesium (Mg), and potassium (K) at a recommended ideal ratio (typically 64:10:5). Although long practiced by farmers, soil balancing is not recommended by most researchers and Extension educators. Our study indicated around half of organic corn growers in the Midwest used a soil balancing approach, but more than 75% of the Extension researchers we surveyed felt soil balancing had no scientific merit.

It’s true that most soil balancing studies done in the past 20 years have reported the practice had no effect on production. However, our research reveals several potential gaps in these studies. Consultants and farmers we interviewed commonly reported that soil balancing improved overall soil quality and structure, which led to improved drainage and reduced weeds. While farmers also reported improved yields and profit, it was generally not the first improvement they mentioned. Interviewees noted that these improvement often happened gradually over several years. In short, past research may not have captured long range positive effects. Most recent studies were short-term, lasting one or two years; were conducted in a greenhouse rather than field; focused only on improved yields; and were conducted on limited types of soils. (Chaganti and Culman, 2017)

We also found that many farmers pair cation balancing with other soil improvement practices such as cover crops and biostimulants. The goal, according to the “balancers” we spoke with, is to improve the physical and biological properties of the soil.

Field Testing

Using both on-farm and Ohio State research station sites, we collected data on soils, weeds, and crops, while applying a variety of soil amendments to change Ca:Mg ratios. We measured crop quality using Brix, color, size, and other characteristics specific to individual crops. Vegetable crops included tomato, butternut squash, cabbage, popcorn, and edamame. Agronomic field crop trials were conducted as well.

We were unable to document any treatment effect on yield or crop quality. In the last year of testing, we did see effects on weed populations (either lower weed populations overall or lower populations of foxtail on “balanced” soils) and on soil root resistance (indicating improved soil structure with higher Ca saturation). These effects appeared only on some fields, but they do support our hypothesis that the positive results of soil balancing are related to improvements in soil structure and drainage. We hope to continue monitoring these fields to see if results become more consistent over time.

Recommendations

For now, we are unable to officially encourage or discourage the use of soil balancing. The following recommendations are based on field trials and on the experience and advice of our stakeholder advisory committee.

  • Soil test data is critical to making informed decisions about what to apply. Some Ohio soils may already have large concentrations of Ca due to Ohio’s limestone bedrock.
  • Watch your pH if using lime. Gypsum is a better choice to change the Ca level without affecting pH and it also provides sulfur.
  • Soils with a CEC below 10 may develop deficiencies. In soils with a low holding capacity for cations, excess Ca can lead quickly to deficiency levels of K, and possibly Mg. We did work in fields with Ca saturations well above 80% and observed K deficiencies in the soil and vegetables in these situations.
  • Consider economic factors. The higher your CEC, the more time and amendments will be needed to increase the Ca:Mg ratio. At some point—depending on the amount of change needed and the value of your crop—using soil balancing becomes an expensive practice.
  • 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.

With widespread use of the practice, soil balancing is a pertinent area for research and cooperative education. Our team hopes to continue studying the practices and long-term effects of soil balancing on a larger variety of soils. Drawing on experiment data and the experience of farmers and consultants, we will work toward guidelines and toward a mutual understanding of soil balancing.

Read more about this study at the Soil Balancing Project Site or the Vegetable Production Systems Laboratory. 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.

 

Growers and Researchers continue to Study Grafted Vegetable Plants

In Ohio, full-time study of grafted vegetable plants as products (i.e., sources of income) and production tools began more than ten years ago. Much has been learned and the popularity of grafted plants continues to trend upward. However, growers and researchers continue to ask many large, detailed, and tough questions about the roles of grafted plants in commercial production going forward. “Do grafted plants pay?” may be the most often asked and significant question. This brief article cannot address that question definitively for all readers due to the specific circumstances of each farm, field, crop, planting, season, etc. However, peoples’ collective understanding of the pros and cons of using grafted plants and of conditions leading to a good return on investment after using them is improving. As it does, success with grafted plants improves and their use increases. Regardless, additional research is needed. The three panels below briefly summarize a portion of the vegetable grafting research underway in Ohio in 2019. Please contact us if you would like to learn more about this work and stay tuned to VegNet and other outlets for updates.

Matt Kleinhenz, ph. 330.263.3810, email kleinhenz.1@osu.edu

Insecticide update for vegetable and fruit crops

There have been a few insecticide registrations that have come through since previous updates this past winter (summaries from January are available with these links: https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2019/02/PAT_Jan2019_1-page-1hvqfhg.pdf and https://cpb-us-w2.wpmucdn.com/u.osu.edu/dist/1/8311/files/2019/02/Summary_Jan2019_1-page-22nf965.pdf ).

Torac and Apta from Nichino America both contain tolfenpyrad as the active ingredient; both are in IRAC’s mode-of-action group 21A. Since March 2019, new crops on the new Torac label are onions and other bulb vegetables, lettuce and other leafy vegetables, and celery and other leaf petiole vegetables. Torac controls thrips, aphids, leafhoppers, flea beetles, and some caterpillars. Since February 2019, new crops on supplemental labels for Apta are strawberry and other low growing berries, raspberries and other caneberries, and blueberries and other bushberries. Apta controls thrips, plum curculio, fruitworms, Lygus (tarnished plant bug), and suppresses spotted-wing Drosophila.

Versys is a new insecticide from BASF that contains afidopyropen as the active ingredient, which puts it in IRAC group 9D. On the initial label in October 2018, the target pests were only aphids, as controlled at a low rate of product. A newer label now includes control of whiteflies at a higher rate of product.

Exirel is now allowed on raspberries and other caneberries, as shown on a supplemental label from November 2018. Use on caneberries is with a 1-day pre-harvest interval, for control of spotted-wing Drosophila and adult root weevils. Exirel is from FMC, and contains cyantraniliprole as the active ingredient, in IRAC group 28.

PQZ is a new insecticide product from Nichino America that has been registered since November 2018 but was missed in our earlier updates. PQZ contains pyrifluquinazon as the active ingredient. It is in IRAC group 9B. It controls aphids, whiteflies, and leafhoppers, and is allowed for use on Brassica head and stem vegetables, cucurbits, fruiting vegetables, leaf petiole vegetables, leafy vegetables, tuber and corm vegetables, as well as on pome fruit, stone fruit, and grapes.

Ethos-3D is a new insecticide/fungicide product from FMC that has been registered since 2018 but was missed in our earlier updates. It is for use on sweet corn. It contains bifenthrin (the same AI as in Brigade; IRAC group 3A) as the insecticidal component, and Bacillus amyloliquefaciens as the fungicidal component. It is for application at-planting for control of corn rootworm larvae, Asiatic garden beetle, wireworms, grubs, seedcorn maggot, cutworms, and armyworms.

-Celeste Welty, Extension Entomologist

Using Cover Crops for Weed Control in Spring

Cover Crops are a valuable tool in the toolbox of the backyard grower, community gardener and urban farmer.  I planted a mix of cover crop species last fall in my community garden plot to keep the soil alive over the winter, prevent erosion and increase soil organic matter.

Winter rye, forage radish, hairy vetch and crimson clover blend

This species mix, especially the winter rye component, can be challenging to manage in the spring depending on when the soil is worked.  The winter rye will die from mowing or crimping when it is going to seed and nearing maturity, but when tilled young, some of the grass will continue to grow.

The city tilled the garden in late March, some of the cover crops persisted and will continue to grow without further tillage or herbicide application.

The majority of my plot will be used for summer vegetables.  I do not want to leave the ground bare until that point as the cover crops will continue to grow in spaces and weeds will fill in the rest.  I would also lose organic matter and fertility from spring rains.

I rototilled over half of the plot to create a seed bed about 10 days after initial tillage.  This will kill most of the remaining over-wintered cover crops and created a seed bed for planting.  There is a loss of organic matter from tillage, but I did not have the option to drill in the seed.

I followed up with a planting of Buckwheat.  Buckwheat is a versatile cover crop that tolerates poor soils, rapidly germinates, weed suppresses, attracts pollinators and when mowed, will rapidly break down prior to the next planted crop.

 

 

I will let the Buckwheat grow until mid-May.  Then I will mow the space which will kill both the cover crop and any annual weed that germinates within the Buckwheat planting.  It will also weaken any perennial weed that is growing.  I will let the residue decompose for a few days and then till and apply plasti-culture mulch in the pathways prior to summer vegetable planting.