Use of Worm Casting Extract in Ag Production

Final Report for FNC04-536

Project Type: Farmer/Rancher
Funds awarded in 2004: $4,048.00
Projected End Date: 12/31/2004
Region: North Central
State: Illinois
Project Coordinator:
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Project Information


Objective: To gather sound and justifiable evidence that the use of worm casting extract may increase production returns while decreasing dependency on synthetic fertilizers and pesticides. Worm casting extract is produced by using pure worm castings, agitating them in water to extract the soluble nutrients and microbes, then using the screened liquid to spray on the soil or corps. This project will concentrate on soybeans, grain sorghum and corn, but it is hoped that the evidence gathered may be utilized in other agricultural production applications as well. Trials were conducted on this farm in the 2003 production year and indicated that there may be less demand for supplemental nitrogen in grain sorghum and wheat when using worm-casting extract. The rate of nitrogen application in wheat was reduced from 120 lbs. per acre where no worm-casting extract was applied to 40 lbs N per acre where 65 gallons of worm-casting extract per acre was applied with no reduction in yield. Although the grain sorghum trials demonstrated a slight reduction in yield where reduced nitrogen applications were used compared to plots where 100 gallons of worm-casting extract was used, the net income was still higher because of the cost savings from the nitrogen reduction. These trials will continue in 2004.

Use of worm casting and worm-casting extract in golf course maintenance has suggested that fertilizer and insecticide use can be reduced by up to 70% with a cost savings of over $40,000 on an 18-hole course. Other recorded observations include repulsion of certain insects in vegetable production.

We have a 230-acre family farm that includes the original 80 acres my father bought in 1940. My wife and four children have all helped with the farming and livestock operations. We had a 150-sow farrow-to-finish hog unit until the hog market crashed in 1998 when we decided to sell off our stock and start something different, vermiculture. We got our first worms in December 1998 and started working with Larry Martin of Vermitechnology Unlimited in 2000. We have worked with him to improve and expand our worm operation so we are able to produce the highest quality, most consistent worm castings that can be produced. In case anybody doesn’t know, worm castings are actually worm manure. We have steadily increased sales of the castings in the last few years. Along with the sales of the castings we are also selling worms into the bait and composting market and manufacturing worm-casting extractors to liquefy the castings. I am working full time here on the farm; my wife helps with the worms, does the books, and has just quit her part time job to be able to spend more time with our business. Our 22-year-old son helps here and has a part time job at a neighbor’s dairy farm. Our sales have increased to the point he is going to be able to quit his part time job and work here full time.

In the late winter of 2003 we started working with Larry Martin in the development of a Worm Casting Extractor. The concept is to take worm castings, agitate them in water to extract the water soluble nutrients and microbes, then screen the liquid and spray on the soil to foliar feed directly to the crop. We gathered information from the compost industry, where they are making compost tea, and refined the information to make it work with our worm castings. In the production of compost tea a person has to multiply the microbes in the compost making them unstable and every batch can be different because of variables in the compost. In the production of the worm casting extract our worm castings are very consistent so we are able to produce a consistent end product. Also, we are not trying to multiply the microbes, only extract them from the castings, which make a more stable product. Compost tea takes 24 hours to produce a batch and needs to be applied as soon as possible after it is made, usually within 12 hours. Our casting extract can be produced in 4 hours and has a shelf life of at least a month, maybe longer. A long term, 6 month, test for the viability of the extract is being done right now. We have also started the process to have the extract labeled as an organic fungicide. We have extractors at golf courses that are connected into their irrigation systems so the extract can be applied when irrigating. Appling the extract this way can control most of the fungus problems on the golf turf along with foliar feeding. The extract is all natural and does not harm the environment from run off or leaching.

The purpose of this grant was to show how the worm casting extract could be used to reduce the amount of synthetic fertilizers used on grain sorghum and soybeans. The castings and casting extract has shown tremendous potential in reducing the use of synthetic fertilizers and fungicides on golf courses and in vegetable production. We have reduced the cost of maintenance over $40,000 a year on an 18-hole course. I want to show how it can be used to reduce costs in row crop production.

I have been testing the extract on a 40 acre field for the previous two years on my own with 20 acres in soybeans and 20 acres in grain sorghum, rotating each year. I started this SARE project with the intention to utilize 40 acres of my neighbor’s land to run additional tests on plots of his corn and beans, but the weather turned wet in the fall of 2004 and I was unable to get the first application of extract onto his fields. I decided to not use his fields and only use my 40 acres. Due to the previous years’ testing I wanted to make my first application of extract in the fall so the microbes would have more time to work before the next year’s crop was planted. I have had positive results for the previous two years in being able to reduce the amount of nitrogen, with some reduction in yield but still above the economic threshold. I was looking forward to using this grant to do soil testing and microbial testing to see if any improvements were being made. On 10/10/04 I was able to get the first application applied at a rate of 50 gallons per acre. I have this field marked into 24 row strips. I have been applying extract to the same 24 row strips for the last two years, alternating extract with non-extract strips.

On 4/05/05 soil tests were taken. My intention was to take tests in the spring and come back in the fall and test again in the same spots. To make the tests as accurate as possible I took the tests in the 3rd repetition strips and used a measuring wheel to pull samples from 300’, 600’, and 900’ from the North end of the field. I took the samples from the middle 12 rows of the 24-row strip. A set of samples was taken from each 20 acres of soybeans and grain sorghum, 3 from the extract strip and 3 from the non-extract strip. An extra set of samples was taken from the 600’ site to send in for microbial testing.

Both the soybeans and grain sorghum were planted using conventional tillage, the soybeans on 5/5 and the grain sorghum on 5/17. Pre-plant herbicides were applied with 40 lbs. of 28% Nitrogen added to the grain sorghum herbicide. On 6/21, 28% N was side dressed to the non-extract plots at a rate of 80 lbs. per acre. On 6/29, 50 gallons of extract was applied to the extract plots. No notable differences were observed in either the soybean or grain sorghum plots during the year.

The soybeans were harvested on 10/2 and all strips were weighed with a weigh wagon. The grain sorghum was harvested on 10/7 and weighed with a weigh wagon. The results are on a following page. [Editor’s Note: For copies of these and other results, please contact NCR-SARE at: or 1-800-529-1342.]

A second set of soil tests were taken on 10/27 in the same areas of the tests on 4/5.

The microbial diversity tests were inconclusive, see results on following page. The casting and casting extract tests were extremely low compared to previous tests that have been run. Previous extract tests have been 8.5 – 9.3 leading to the conclusion something went wrong with these tests. Preliminary tests on extract the longevity tests have been much higher. Final results will not be available till late winter or spring.

The soil tests were more interesting. A following page has detailed information. Almost all of the tests show a higher result where the extract was used. No added fertilizer, except for 28% nitrogen added to the non-extract strips, has been used in the last three years. You cannot make conclusions on one-year tests, but it does warrant more study and multi-year testing to see if the results continue.

The yield and cost/benefit analysis is on a following page. It does show that you can reduce the nitrogen and not reduce the yield enough to get below the economic threshold on grain sorghum. I have had similar results the previous 2 years. The extract did not show any advantage when used on the soybeans, which is also similar to the previous 2 years. More testing needs to be done to see if the advantage in nitrogen reduction was from the extract or other variables.

The worm casting extract is no miracle cure for the row crop farmer, but it does have the possibility of being able to reduce the amount of fertilizers being applied to the land. Any reduction in the use of the fertilizer applied will save the farmer money along with being able to reduce the amount of fertilizer that is being lost through leaching and runoff that is polluting our rivers and oceans. The microbes in the soil have been so depleted over the years that the farmer has to keep applying more and more fertilizer to produce a crop. The extract has the potential to increase the microbial populations which should make more of the fertilizer that is already in the soil available to the plant. More detailed and controlled testing needs to be done to see if worm casting extract can be a viable addition to row crop production.

I plan to focus my outreach for this project on writing articles for newsletters and doing presentations at meetings. I participated in a segment at the sustainable ag meeting in Effingham, IL last year. I have just sent in my proposal to be an oral presenter at the SARE national conference in August 2006.

Kim Tack, of the U of I Extension, published an article about us in his spring 2005 “IDEA” newsletter. We are going to do an article in Deborah Cavanaugh-Grant’s “Agro Ecology” newsletter.

I feel articles or presentations are the best way I can reach people who are truly interested in what we are doing. Hopefully I will be able to do more presentations at sustainable ag seminars or other venues to let people know there are alternatives to conventional farming practices.

If anyone has any questions, comments, or would like more information please feel free to contact us @ 217-683-2336.

Microbial Tests – Microbe Diversity
Sample #, With Extract, No Extract

Soil – W5, 9.2
Soil – WO-5, 9.2
Soil – W2, 8.5
Soil – WO-2, 9.1
Worm Casting 5.6
Casting Extract 5.0

Microbial tests were inconclusive. Worm casting and extract tests were extremely low compared to previous tests run. All previous worm casting extract tests were between 8.5 and 9.3, this would lead me to believe there were either errors in the testing or something contaminated the sample.

A second set of tests are being performed now to test the longevity of the casting extract. The test is for 6 months and will conclude in late winter. The first initial tests were very good.


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.