This project will test the efficacy of using compost, as a mulch and weed suppressor, in small-scale no-till vegetable production.

Final report for FNC22-1355

Project Type: Farmer/Rancher
Funds awarded in 2022: $15,000.00
Projected End Date: 12/15/2024
Grant Recipient: Pine Creek Farms LLC
Region: North Central
State: Minnesota
Project Coordinator:
Jonathan Stensgard
Pine Creek Farms LLC
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Project Information

Description of operation:

Pine Creek is a small 3-acre vegetable farm, entering its ninth season, consisting of owners Jonathan Stensgard and Jordan Flynn. After working on organic farms in Oregon and Minnesota, we decided to start our own farm back home in Southeastern Minnesota. Over the past several years, we have become a successful small-scale vegetable farm through our CSA program, Farmers Market, and wholesale accounts, which include: local restaurants, co-ops, and grocery stores, such as Hy-vee and Natural Grocers. We grow many different varieties of produce, but our most profitable crops include tomatoes, lettuce, and spinach. We love what we do, and we hope to continually help build our community in a positive way.

Summary:

  Before we were even accepted for the Farmer and Rancher Grant, we have witness first hand, from a visual standpoint, how much over tilling can affect soil structure. The soil is more prone to erosion, drying out, and has always seemed to yield less than when planting into ground that has just come out of a succession of cover crop. This grant gave us the opportunity to take a closer look on what is actually happening every time you till soil and if that will have an adverse affect on both soil structure and the biome that is crucial in the relationship between your roots and the nutrients it needs. It also let us see if compost left on the soil surface could be used as a mulch and weed suppressor, which would hopefully improve yields and time spent in the field weeding and tilling. Overall we were left with mixed results. 

  We began the process with building a self loading compost bin/spreader (video - https://www.youtube.com/watch?v=vcU8c44xQhI). In the beginning we envisioned the spreader having the capability to spread the compost automatically using an auger system. It is important in our permanent bed system to apply the compost directly on our raised beds and not in the walkways. After some further investigating we found that the compost we purchase is usually too heavy/wet and it would end up bridging, which would become a nuisance. We would like add that if the compost used was finer or dryer it might be possible to use a manure spreader or auger system compost spreader. In the end, the compost spreader we designed and built worked great! It became a two man operation but it was very efficient and enabled us to spread the compost directly over our raised beds, right where we need it. Two loads with the spreader was enough to cover one of our hundred foot beds but it could be made larger depending on your tractors power and size. It can even be used in the high tunnels which is a huge plus considering that in the past we carried the compost in by the bucket load. As we have always done in the beginning stages of trying something new, we hope that another farmer out there will stumble across our video on YouTube and have an idea of where to start. 

   The next part of the process was planting into the trial and control beds which were in large plots on an every other bed basis. The control beds had compost applied and that compost was tilled into a six inch depth. The trial or test beds had compost applied but the compost was left on top of the soil in hopes to create a weed suppressor or mulch. We found that not tilling the trial beds saved our farm about seven minutes per bed. During the average season we plant roughly eighty five hundred foot beds which would end up being about ten hours worth of tilling just for lettuce, which is quite substantial. Each week we planted successions of lettuce into the control and test beds at the same time and each bed in those successions were watered and weeded at the same time as well. After some time, we realized that after hard rains, the compost left on top of the trial beds would become rock hard, which made it difficult to transplant the lettuce into. The hard compost also seemed to make it difficult to weed with our hand held hoeing tools. Eventually, we were forced to use a tilther, which is a small drill powered tool that breaks up the top inch of soil. The soil beneath the compost was untouched as to not affect the trials. The time spent tilthing did offset the time spent not tilling the trial beds, so in the end, we did not save any time. If an auger type compost spreader was used it is possible that it would have broken up these larger pieces of compost while spreading it at a more consistent rate and may have made it possible to avoid tilthing. Another downfall of leaving the compost on the soil surface was that, after a hard rain, the compost seemed to have an increased chance of eroding into the walk ways between each bed compared to the beds with tilled-in compost. Throughout the process we shared our experiences on our social media pages so that other farmers or people interested could learn from our findings. 

   Overall, the trial beds did show some promising signs when it came to using the compost as a weed suppressant. On a scale from one to five, one being the least amount of weed pressure and five having the highest amount of weed pressure, the test beds had a somewhat lower rating with 1.75, while the control beds, beds where the compost was tilled in, had a rating of 2.38. On average, each bed was manually weeded once throughout the lettuce lifespan, so therefore, time spent weeding was not affected as far as times weeded, though the control beds with a higher weed pressure rating most definitely took longer to weed in general. Looking back, the actual time spent weeding each individual bed would have been a better way to document and would have given us a better picture of how much time using compost as a mulch was actually saving us. We also attempted to measure disease pressure for each bed. This was inconclusive as plot one used in our trials was hit with hail in later July of 2024. The successions before hand in plot one had all battled with disease at an equal rate. This was mainly due to the heavy rains and storms our area was hit with during most of the growing season. In plot two, neither the test or control beds showed higher signs of disease resistance. 

   The most crucial part of our documentation was to see if using compost as a weed suppressant and mulch would lead to higher yields. Keeping in mind that seven of the thirty four total beds monitored were affected by a large hail storm, the test beds did indeed show quite a rise in overall yields. Throughout the two plots, the control beds planted with salad mix yielded an average of 44.5 lbs harvested per one hundred foot bed while the test beds planted with salad mix showed an average of 49.5 lbs harvested per one hundred foot bed. Additionally, control plots planted with head lettuce yielded an average of 64 heads harvested per one hundred foot bed while the test beds planted with head lettuce yielded an average of 87 heads per one hundred foot bed. Though it may be a small margin, any system that may increase crop yields in a small organic vegetable farm needs to be considered. More monitoring would be needed to determine if this type of system would lead to overall higher yields throughout different seasons and in crops other than lettuce. 

Project Objectives:
  1. Evaluate the efficacy of using compost, as both a mulch and weed suppressor.
  2. Evaluate if such practices will promote higher yields and profits, while cutting down on work load, such as weeding and tilling. 
  3. Share our findings with the community, and other farmers, through an on-farm showcase, social media, and our local newspaper, as well as posting a DIY construction video of our Self-Loading Compost Spreader design. 

Research

Materials and methods:

  Each week we transplanted lettuce into control and trial or test beds. Control beds consisted of permanent beds where compost was applied then incorporated into the soil through tillage. The trial beds consisted of permanent beds that were top dressed with compost in hopes that the compost could be used as a mulch and weed suppressant. Each succession of control and trial beds were seeded, transplanted, watered, weeded, and documented on the same day to promote consistency in the results. We then documented bed prep time spent, weed pressure, disease pressure, and yields. Soil samples were taken in the spring (before compost application and tillage) and then again in the fall to measure the effects tillage can have on the overall soil structure.

Research results and discussion:

  Overall the trial beds where the compost was not tilled in did see a decrease in weed pressure. On a scale from one to five, one being the least amount of weed pressure and five having the highest amount of weed pressure, the test beds had a somewhat lower rating with 1.75, while the control beds, beds where the compost was tilled in, had a rating of 2.38. On average, each bed was manually weeded once throughout the lettuce lifespan, so therefore, time spent weeding was not affected as far as times weeded, though the control beds with a higher weed pressure rating most definitely took longer to weed in general.

   Keeping in mind that seven of the thirty four total beds monitored were affected by a large hail storm, the test beds did indeed show quite a rise in overall yields. Throughout the two plots, the control beds planted with salad mix yielded an average of 44.5 lbs harvested per one hundred foot bed while the test beds planted with salad mix showed an average of 49.5 lbs harvested per one hundred foot bed. Additionally, control plots planted with head lettuce yielded an average of 64 heads harvested per one hundred foot bed while the test beds planted with head lettuce yielded an average of 87 heads per one hundred foot bed.

 

  Please see attached documents for soil samples and documentation of weed pressure, disease pressure, and yields. (Treatment results and samples refer to the trial beds where compost was top dressed and not tilled into the soil) 

Field Documents: Grant Recording Sheet - Plot One , Grant Recording Sheet - Plot Two

Soil Samples: PCO Plot #4 Treatment Results_2024-10-09 PCO Plot #4 Control Results_2024-10-09PCO Plot #3 Treatment Results_2024-10-09PCO - Plot#3 Control Results_2024-10-09

 

Erik Harris of CVRFS who conducted the soil samples had this to say: 

Biological comparison of the control and treatment on plots 3 and 4 - 
Plot #3
Both control and treatment have good numbers of bacteria and nematodes.  Treatment samples showed higher fungi to bacteria ratio and higher number of fungi per gram of soil.  This indicates that your method, at least in Plot  #3, was effective.  The chemistry also shows higher Organic Matter in the treatment, but only slightly. (4.7 Ctrl, 4.8 Treat), and slightly higher Ca:Mg ratio.  Both of these indicate that nutrients are held better and can be translocated more effectively.  
 
Plot #4
Although both control and treatment have good bacteria numbers neither have nematodes.  In this plot, control has higher fungal numbers compared to treatment.  The fungal to bacteria ratio is also higher in the control.  Control also shows the presence of protozoa.  This indicates that your method was ineffective.  The chemistry follows similar trends.  Organic Matter is higher in the control sample (6.9 ctrl and 6.5 Treat), and similar Ca:Mg ratios.  
 
So, it seems that between plots 3 and 4 there is contradictory evidence between topp dressing and integration methods.  Good news is both soils have improved in terms of Biology since we ran a sample in the spring.  
Participation Summary
2 Farmers participating in research

Educational & Outreach Activities

1 On-farm demonstrations
2 Online trainings
1 Published press articles, newsletters

Participation Summary:

10 Farmers participated
3 Ag professionals participated
Education/outreach description:

  Social outreach was a big part of what we wanted to accomplish with the opportunity that the Farmer and Rancher Grant gave us.  Throughout the entirety of the grant process, we shared our findings on our social media using pictures and videos to describe the trials we were conducting on the farm. In the spring, we started off by making a how-to video on our experience building the compost box/spreader that we designed specifically for the grant. Cloey Walsh, of Clomotion Pictures, produced a short video that was shared on the farm's social media and YouTube. Here is a link to the video https://m.youtube.com/watch?v=vcU8c44xQhI&feature=youtu.be

   On September 18th, John Seivers, of the Post Bulletin, a local newspaper in Rochester Minnesota, released an article about our grant proposal and other sustainable practices we are currently trying to achieve. The article also talked about our relationship with Erik Harris, of Clear View Regenerative Farms and Services, who took soil tests throughout the grant to show how no-till practices may or may not affect soil structure. Here is a link to the article https://www.postbulletin.com/business/plainviews-small-farm-with-big-dreams

  Later that month, on September 23rd, we held a grant showcase on the farm. Erik Harris was there talking with participants about certain practices that will lead to a healthy social structure and biome. Participants were very involved in the conversations and were seen taking notes. Cloey Walsh, of Clomotion Pictures, was present to take pictures, videos, and notes to later post on the farm's social media. Here is a link to the farms Facebook page - https://www.facebook.com/seminnesota/

 

Learning Outcomes

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

Compost Spreader: After some further investigating we found that the compost we purchase is usually too heavy/wet and it would end up bridging, which would become a nuisance. We would like add that if the compost was finer or dryer it might be possible to use a manure spreader or auger system compost spreader. In the end, the compost spreader we designed and built worked great! It became a two man operation but was very efficient and enabled us to spread the compost directly over our raised beds, right where we needed it.

Applied compost/transplanting into compost: After some time, we realized that after hard rains the compost left on top of the trial beds would become rock hard, which made it difficult to transplant the lettuce into. The hard compost also seemed to make it difficult to weed with our hand held hoeing tools. Eventually, we were forced to use a tilther, which is a small drill powered tool that breaks up the top inch of soil. The soil beneath the compost was untouched as to not affect the trials. The time spent tilthing did offset the time spent not tilling the trial beds, so in the end, we did not save any time. Another downfall of leaving the compost on the soil surface was that, after a hard rain, the compost seemed to have an increased chance of eroding into the walk ways between each bed compared to the beds with tilled-in compost.

Weed pressure/Disease pressure/Yields: Unfortunately, due to hail storms in the summer of 2024, our statistics were somewhat inconclusive. However, from the information gathered, the trials beds did show a decline in weed pressure through out the grant process. On average, each of the trial and control beds were manually weeded once throughout the lettuce lifespan, so therefore, time spent weeding was not affected as far as times weeded, though the control beds with a higher weed pressure rating most definitely took longer to weed in general. Looking back, the actual time spent weeding each individual bed would have been a better way to document and give us a better picture of how much time using compost as a mulch was actually saving us. Throughout the two plots, the control beds planted with salad mix yielded an average of 44.5 lbs harvested per one hundred foot bed while the test beds planted with salad mix showed an average of 49.5 lbs harvested per one hundred foot bed. Additionally, control plots planted with head lettuce yielded an average of 64 heads harvested per one hundred foot bed while the test beds planted with head lettuce yielded an average of 87 heads per one hundred foot bed. More trials would be needed to see if this no-till compost system would lead to higher yields across all crops grown on a vegetable farm. 

 

 

 

Project Outcomes

1 Farmers changed or adopted a practice
1 New working collaboration
Recommendations:

   Pine Creek Farms has concluded that using compost as a mulch and weed suppressor can be beneficial in the right situations such as high tunnel or greenhouse production where erosion and the hardening of compost is not an issue. We have been using no till practices in our high tunnels for several years now with great results. Our overall weed pressure has declined, the amount of bed preparation has decreased, and yields have continued to rise. The compact self loading spreader that we built for this grant, which enables you to reach the tightest of corners, has only made it easier to apply the compost.

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.