Utilization of Worm Tea on Field Scale Trials for Soil Remediation

Progress report for FNC22-1324

Project Type: Farmer/Rancher
Funds awarded in 2022: $10,370.00
Projected End Date: 01/15/2024
Grant Recipient: Duncan's Worm Farm
Region: North Central
State: Indiana
Project Coordinator:
Stephanie Duncan
Duncan's Worm Farm
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Project Information

Description of operation:

Stephanie Duncan: I have been worm farming since 2018. In 2020 we started Duncan's worm farm. Mark and I have a small scale business. We started selling worm tea the summer of 2021. We have approximately 50-60 thousand composting red worms. We collect used card board and use as bedding for our worm beds.


Farmers Jason Mann and Stephanie Duncan propose to collaborate to examine the benefits of worm tea in a field crop agricultural setting.  In order to accomplish this goal, Mr. Mann will dedicate 1.5 acres of corn/wheat/soybean rotation ground.  Ms. Duncan will produce worm tea in a concentrated form.  Mr. Mann will apply the tea preplanting and at planting in a strip trial with two strips of treatment and one strip of control.  The crop will be assessed throughout the growing season for plant nutrient content with soils being testing after harvest.  The second-year treatments will be conducted similarly. Approximately one-half of the plot is disturbed soil needing remediation, while the other half is medium-to-high productivity soil.  In this manner, we can assess worm tea as a crop nutrient across very different soils.  Although worm tea is currently an expensive fertilizer, success with this experiment may allow for some utility bringing poor soils organic matter and a quicker return to economic viability.  The substitution of synthetic commercial fertilizers for worm tea may be an ecologically sounds and socially responsible choice for some areas where economies of scale can develop.

Project Objectives:
  1. Assess the value of worm tea in large-scale agricultural farm management.
  2. Evaluate plant and soil chemistry and biology in two soil types under traditional and worm tea amended management.
  3. Explore the economic viability of worm tea in certain agronomic situations.


Click linked name(s) to expand/collapse or show everyone's info
  • Hans Schmitz - Technical Advisor (Educator)
  • Aaron Neufelder - Technical Advisor (Educator)


Materials and methods:

sprayer used to spray tea on field field prior to any applications tea .  March tubs of worm tea prior to loading into planter in furrow planting of corn Corn , June 25th,2022

Saturday March 19,2022

We met Jason Mann and Hans Schmitz at the project site at 11 AM.
Jason pointed out the condition of the field. We discussed which zones we would be treating
with worm tea. There is a fescue currently planted as a cover crop. I did not want Jason to use
a herbicide to kill off the cover crop. After discussing with Hans we decided Jason would till crop
under since it was time to level the field up some.

Jason provided us with some previous soil sample results to have a reference for our project.
We will be marking off the field into treatment sections after Jason tills the field. Jason will have the
soil sampling done at that time as well. Once the soil sample is taken we will apply worm tea.
I took a few pictures of the field , the pictures show the trouble areas where soil quality is poor.

Sunday May 08, 2022, Initial spraying of worm tea extract

We loaded 60 gallons of water, 2, 15 gallon tubs, Transfer pump, 4 worm tea bags with 10 cups of Worm castings each bag, Organic Liquid Humic Acid , Hydrolyzed Fish and Seaweed Blend.   Met with Jason Mann (farmer) at the field site at 4 pm. Jason had a 45 gallon 7 nozzle boom sprayer on a Side by Side ATV.  The Sprayer was set up with fine tip sprayer nozzles.

We used a transfer pump to fill a 15 gallon tub with water (well water).  I massaged worm casting tea bags until most of the castings had liquified, then added ¼ cup of hydrolyzed fish and seaweed blend and ¼ cup liquid humic acid.  The first Tea Bag did not seal well enough and some larger sized casting and Worm cocoons got into the tub.  We use the transfer pump to pump worm casting extract directly into the sprayer.  Mark held a painter's Strainer bag over the sprayers’ fill whole to catch any larger particles possibly left in the Tea extract.  We repeated this process 3 times until the Sprayer tank had approximately 35 gallons in it.  

We had Jason remove all inline nozzle filters as well as the tank filter.  We tested flow rate prior to entering the field, and the flow was good.  Jason was able to spray approximately ⅓ of the field when the 2 outer sprayers became clogged.  We were able to remove debris with a nozzle probe.  However it continued to clog.   We then determined the fine mist nozzle was too small.  We pumped out the sprayer and cleaned the tank with clean water.  Jason replaced the sprayer nozzle tips with larger tip openings.  He finished spraying the field with little trouble.  We then discussed how we could improve the process for future sprays.

We decided that we needed to replace the heavy duty garden hoses used for the transfer pump.  Jason was going to get a braided hose to prevent the hose from collapsing.  I ordered a 5.7 inch by 7 inch  pool strainer basket to use as a filter holder to insert in sprayers fill whole while loading tea extract.  We are hoping this will speed up the fill process as well as free up a person from holding the bag while filling the tank.  We also will be mindful to not suck the larger silt from the bottom of the mixture while filling the sprayer tank.

Jason is planning on planting the field later this week pending weather.  We will be using tea extract in furrow while planting corn.  We were at the field for approximately 2 hours. 

May 14th,2022 

 We met Jason Mann (farmer) at his farm shop on May 14th, 2022.   We brought a 60 gallon tank of well water,  2 20 gallon tubs for mixing worm extract in.  We used 20 cups of worm castings and 1 cup of each  liquid humic acid and hydrolyzed fish and seaweed blend.   

We made approximately 50 gallons of Worm tea.  We connected a transfer pump to load directly to the  planters’  tank.   The planter had two 275 gallon tanks on it however we only used one side.  We loaded 50 gallons of Worm tea into the planters’ tank.  We changed out  the sprayer nozzles to a 70 orifice , there were no inline filters, only a  pump filter.   Jason set the flow rate to 15 GPA at 25 psi.  We headed over to the field site.  Hans Schmitz met us at the field site. Jason primed the pump then made a pass around the field to set the tractor's GPS.  After the tractor was programmed Jason lined the tractor up to the middle section of the test plot which would be planted with worm tea in-furrow.   We had to change a couple of the sprayer nozzles that were not working properly.  Once the planter was operating properly he planted the center section in-furrow.  The 2 outside swipes were not planted in-furrow as the control .

The whole process from setup to finish was about 2 .5 hours due to some technical difficulties.   

There was approximately 20 gallons of tea left after planting was completed.  Jason drained remaining tea into his ATV sprayer and sprayed it over the center test section that evening.  Jason cleaned the planter tank and spray lines with bleach water as well as the ATV sprayer.   

Jason reported that corn was up 5 -6 days after planting.  We had a good stand. 

June 18th, 2022  Last application of worm tea 

We brewed 45 gallons of Worm Tea ,  We used 20 cups of worm castings,  1 cup humic acid and 1 cup of seaweed/hydrolyzed fish blend in 45 gallons of unchlorinated water.  Aerated mixture for 24 hours in a 60 gallon water tank.  We delivered tea to Jason (farmer), he loaded it in a 45 gallon ag sprayer which was on back of his side by side ATV vehicle with  a 7 nozzle boom.  Jason applied 45 gallons of worm to the standing 40 foot strip of our test plot.   

September 24th,2022  Harvested Field

Harvest was made difficult by weed pressure due to lack of in-season weed control.  Fall panicum in particular was a problem weed.  

250 lbs P& 200 lbs K applications were made post-harvest around wheat planting.

October 14th, 2022 Winter Wheat Planted

Vertical tillage was used immediately prior and post broadcast wheat planting.

January 7, 2023 Winter Meeting between advisors and farmers

Research results and discussion:

65102 River Bend Ag - CBW01O_TM-TEST

Corn yield in the treated plot was 11 bu/acre.  Corn yield outside the treated plot was 37 bu/acre.  The lack of yield in the treatment was due mostly to sun exposure allowing weeds to thrive more so than in the partially shaded control.  Drought and flooding also played a role in the low corn yields in 2022, particularly wet weather during stand establishment.  The rest of the adjacent field averaged 138 bu/acre.  Winter wheat was planted on October 14, 2022, with a meeting to alter weed control methods held in early 2023.

Participation Summary
3 Farmers participating in research

Educational & Outreach Activities

Participation Summary:

3 Farmers participated
3 Ag professionals participated

Learning Outcomes

4 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Lessons Learned:

One of the biggest hurdles we had was finding a local source for testing of soil, tea and compost. I was unable find a laboratory to professionally test Worm Tea.  Worm Tea should be tested within hours from when the brewing process is completed, so we were unable to mail in. I was able to view under microscope at our farm. We ordered a complete microbial soil test, soil samples were taken prior to planting. It took over 10 weeks to get results.  

When we tried to spray the field the 1st time we clogged up the sprayer nozzles.  We needed to remove all inline filters and make sure we had a larger spray nozzle on. Before loading the tea into the sprayer make sure to use a finer filter.

Weed control cannot be overemphasized.  Despite potential disruption in biological activity, chemical weed control was needed.  Weeds were the number one reduction in corn yield in 2022.

More preparation for precision guidance systems would have created greater ease of in-season application of worm tea.  

Project Outcomes

1 New working collaboration

Recommend using traditional weed control methods despite potential disruption of biological activity, at least for initial research projects.

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.