Optimal Amount of Corn Gluten Meal for Weed Control and Soil Amendment Qualities in Organic Production of Strawberries

Final Report for FNC98-244

Project Type: Farmer/Rancher
Funds awarded in 1998: $4,996.00
Projected End Date: 12/31/2000
Region: North Central
State: Missouri
Project Coordinator:
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Project Information


We are an OCIA Certified Organic Farm, raising a variety of vegetables and fruits. The farm is 52 acres of timber and pasture in southwest Missouri, located between the towns of Nevada, Eldorado Springs and Stockton Lake. We cultivate approximately 10 acres and run pastured poultry with cattle. The farm is run by Dan my husband and myself with the help of friends and family during the peak periods.

We have been working toward a sustainable operation with no outside inputs to the farm. The addition of the pastured poultry last year we have moved one step closer to this goal.

This project was an attempt to determine the effect of corn gluten meal as a pre-emergent herbicide as well as any soil amendment qualities it may posses in the production of strawberries.

In the fall of 1998 we determined that strawberries would go and put in a cover crop of buckwheat to prepare the ground. In April of 1999 we plowed the area, applied turkey manure and lime. The week of planting we created 15 raised beds. On April 24th we held a field day and planted the strawberries. Corn gluten meal was applied on April 25th. On both the planting day and the day we applied the corn gluten meal we received 6-8 inches of rain. We decided to reapply the corn gluten meal; because observation indicated it washed into the areas between the raised beds. The corn gluten meal was again applied on April. That night we received another 5 inches of rain. Instead of reapplying we decided to go ahead and mulch the strawberry beds. There were 5 beds total each receiving different amounts of corn gluten meal.

Plot 1 – control plot
Plot 2 – 5 lbs/1000 sq ft
Plot 3 – 10 lbs/1000 sq ft
Plot 4 – 20 lbs/1000 sq ft
Plot 5 – 30 lbs/1000 sq ft

Each week number of weeds were counted, and pictures were taken to determine the effectiveness of the corn gluten meal. A soil sample was taken at the start before the corn gluten meal was applied and after the season.

The following people/organizations were invaluable in the completion of this project.
- Patrick Byers (Chairperson), Department of Fruit Science, Southwest Missouri State University, Mountain Grove, Missouri. Arranged for us to present our findings at the 2000 Missouri Small Fruit Conference.
- Don Reck (Director), Bridging the Gap, Kansas City, Missouri. Assisted in the arrangements of the field day
- The Eldorado Spring Sun. Advertised for the field day and covered the day in the paper.
- Raul Hernandez (friend), Milo, Missouri, helped haul hay and straw to the farm, helped with the field day and many other small tedious jobs.

This project had small successes and one major failure. In the weekly counting of weeds it became obvious the corn gluten meal was having an effect. For plantain, pigweed, lambs quarters and bull nettles a noticeable decrease was observed, particularly in the lambs quarters. Unfortunately, approximately 4 weeks into the project we began to see foxtail grass, lots of grass. By the end of June it has almost completely taken over the patch.

As an organic grower with hand weeding and mulching the only other options available to us for weed control, the corn gluten meal appears to be a viable option. We had hoped for greater control of the weeds but further research has shed some light in what went wrong.

Wet, wet, wet, it appears that in extremely wet conditions like we had, weeds are not as affected by the inhibiting effects of the corn gluten meal. It is suggested that when things start to dry out that corn gluten meal be reapplied. Careful on this issue, since too dry will reduce the effect of the corn gluten meal as well, in a drought condition it needs to be watered in. I would also apply the corn gluten meal more often. We did two applications, one at the beginning and another on the 5th of June. I have found out that it should be applied every 1-2 weeks for 3 to 4 applications initially depending on weather conditions and weed types. This applies to the timing issue; corn gluten meal is only effective if applied prior to weed germination. You need to know what weeds you are trying to control and apply the corn gluten meal 2 to 3 weeks before average germination date.

One note of interest was that no weeds appeared in the areas between the raised beds. We feel it was because our corn gluten meal “floated” down into this area.

The second part of the project was to determine what if any effect the corn gluten meal had as a soil amendment. Our soil test results showed no difference in residual nitrogen. Field observation however showed the beds with the higher levels of applied corn gluten meal had healthier plants with more runners indicating higher nitrogen levels.

Weed control for an organic farmer will continue to be the largest expense they incur. Even with the promising results of corn gluten meal, in this and other studies, with the event of GMO’s the organic farmer is banned from using it unless the corn gluten meal comes from a certified organic store. This makes an already expensive product out of reach for the average family farm.

For effective use of corn gluten meal the following things need to be carefully considered. The type of weeds and their average germination date, corn gluten meal should be applied a couple of weeks prior to that date. Weather, wet, dry or mild weather can adversely affect the control gained by the use of corn gluten meal. Too wet the corn gluten needs to be reapplied more often, too dry and you need to water in the corn gluten meal. Mild weather can cause weeds to germinate earlier than expected eliminating the effects of the corn gluten meal.

The advantages are real, no damage to the environment has been observed. There appears to be no nitrogen residuals to contaminate our ground water and it is a waste product of the corn milling process. Even with partial control of weeds the amount of time spent weeding will be reduced allowing the organic growers to spend time on other farm or perhaps leisure activities. Still more expensive than a chemical herbicide however, there can be no price put on the good feeling you get form doing the right thing. It could be used for conventional growers as part of a program to reduce the use of chemical herbicides.

We held a field day on April 24th. We contacted the newspaper who ran a notice inviting people out to the farm. We also contacted all our neighbors, Bridging the Gap and the Food Circle in Kansas City, MO. We had a total of 15 people show up to help plant the strawberries and discuss the project. The newspaper came out and took pictures of the days events.

During market days during the summer we spoke with all our customers about the project. Letting them know we were doing on it and that the strawberries they would buy from us would be free from chemicals. The Barstow School Market we attended reached approximately 500 people per week. We also put information about the project in our brochure.

We spoke at the 2000 Missouri Small Fruit Conference on February 23rd, giving the results of the project along with discussion with the participants. Total attendance was 97 people not including University personnel and other speakers.

We have been invited to speak at a food circle meeting this summer to discuss this project and the lessons learned.


Participation Summary
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.