Evolution of Rotary Spader as Primary Tillage Tool in Various Soils

Final report for FNC92-026

Project Type: Farmer/Rancher
Funds awarded in 1992: $2,430.00
Projected End Date: 12/31/1994
Matching Non-Federal Funds: $12,550.00
Grant Recipient: The Lake-Geauga CSA Project
Region: North Central
State: Ohio
Project Coordinator:
Christopher Werronen
The Lake-Geauga CSA Project (1992) SOLDIERS TO SAWYERS LLC 501C19 PUBLIC CHARITY (2013-2019)
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Project Information

Description of operation:

All farms in this research study have interest in and have past experience in soil regeneration, composting, green manure cropping, etc. All farmers have deep interest in the ecological impact of primary tillage tools used on their farms. The concern and general interest in protection and education is in focus. All farms are in production on diversified vegetables, most in raised beds.

Project Objectives:

Our project goal for this co-op grant research project will be to study a great deal of anticipated values of the Rotary Spader Tillage tool. With primary intent to fully disclose all the short-term and long-term effects on soil ecology this tool provides, in direct comparison to the moldboard plow and rototiller. We as a number of farms, with greatly varying soil types, drainage, etc., expect to compile supporting documentation as to the values in primary tillage this tool can offer.  Funding to purchase a spader small enough to allow tractors of 15-20 hp range, will provide clear trial documentation that small family farms with small tractors can allow their sustainable methods the necessary technology to improve soil ecology. 


Multi-farm study with interactivity from a number of growers will help greatly in data researching. Development of technological study results will continue over many years. Some obvious results will be anticipated, including crop production increases due to:

  1. Better drainage: the spader is said to penetrate hard pans and greatly improve the water perculation through natural capillary activity.
  2. Primary tillage using the rotary spader even when soil moisture levels are too high for moldboard or rototiller useage should provide early planting and less damage and mixing of soil topsoil and subsoils. 
  3. Through useage of the rotary tiller, we expect less field travel, less soil compaction, less fuel consumption, and a more ecological process of diversified crop production. 


Click linked name(s) to expand/collapse or show everyone's info
  • Dr. Darwn Kelsey - Technical Advisor (Researcher)
  • Dr. Darwin Kelsey (Researcher)


Materials and methods:

This 1992 SARE grant study request was reduced by 60% to $2,430.00. I did not own and could not purchase a rotary sprader for that amount. So I requested Research help from the local County Park service. Would they purchase and study this tool for SARE. They agreed and I provided all funds from this grant directly toward the purchase of a new Italian built Celli Rotary Spader by Lake Farmpark. The Park service agreed to provide public demonstrations during field days. They also agreed to keep this tool serviced and managed any research studies conducted by Lake Farmpark staff. Darwin Kelsey (deceased) was the Principle Administrator and supported the financial purchase along with this SARE grant. They purchased a new Celli Rotary Spader as the Principle research conducted by Lake County Ohio Metroparks. Dr. Kelsey also ordered a custom gear reduction modification to be made on the Farmpark owned John Deere 45 hp 4 wd tractor.

Over the course of the next 7 years Dr. Kelsey and myself were involved in discussions supporting Public demonstrations of this Rotary Spader. I provided SARE documents as best exposure at public events conducted by the FarmPark. This was in my view excellent use of USDA funds and SARE public exposure to the versatility of spader use in raised bed Farm Park gardens and field plantings. Due to the nature of the operations at Farmpark, I was only a participant witness as the use of the Celli spader was carried out by the staff under Administrator Darwin Kelsey. His staff maintained the record keeping of this Rotary Spader and other Park departments also borrowed the tractor/spader as widely extensive use. At least three sets of (8) spades were replaced during this period of time and Farmpark records show all necessary service maintenance was regularly completed by Park staff. During the years 1993-2000, I heard no negative reports about the Rotary Spader usage performance when it had good shovel metal. Staff at the garden plantings preferred not to moldboard plow the gardens in the spring as the Rotary Spader was their choice for tillage. Furthermore the Rotary Spader could work right through wet clay soils, often a problem for moldboard plows during early spring tillage plowing. Once the soil warmed up the rotary spader was valued over plowing or rototiller use too.

In 2001 Dr. Kelsey left the Farmpark as head Administrator to take a new position at the the Cuyahoga Valley National Park as their first farm Director. I was a volunteer at the Farmpark until 2000 and lost contact with him and the Rotary Spader remained in use by the Metroparks. However in 2017, I inquired about this Celli Rotary Spader and its use at Lake Farmpark. I was introduced to the current Administrator Lee Homyock and he informed me that after 20 years the Celli Rotary Spader was no longer being used. This may because new staff were unfamiliar that the Spader required a new set of (8) shovels. The current staff had determined the Spader would go to public auction soon.

I requested an opportunity to continue further Rotary Spader research off the Farmpark property. This would happen through a transfer of ownership to Soldiers to Sawyers 501c19 non profit which I founded in 2013. Farmpark administration agreed to proceed with transfer paperwork, and this 1992 Celli Rotary Spader was then transported to the S2S location for final report studies. Unfortunately there was no budget available to purchase replacement shovels, but we found all (8) shovels were still in working order. I then performed a full maintenance restoration on this spader tool and could not find ANY welding or repairs of broken crankshaft or shovel arms. Gearbox was in excellent condition likely because the P.T.O. shaft had a slip clutch disk which engaged when any large rocks would lock up the drive motion. Sheet metal was in very good condition but need a primer paint then fresh coat of John Deere green paint. S2S did not own a large tractor with adequate power to run this Rotary Spader, but a friend and fellow farm researcher Mr. Ted Calkins stepped in with his Oliver tractor. Below is a link to photos and videos.   https://photos.app.goo.gl/MQXCs1vxoQrt3eoW8        

Research results and discussion:

Summary: I conducted a field examination of this Celli Rotary Spader now fully serviced for this Final Report. One drawback is these Celli Italian imported farm tools are expensive. Last check on current prices for similar new replacement, was $15k. As a final note, this tool provides sustainable tillage for soil fertility building. It does as advertised, it breaks the hard-pan created from years of moldboard shallow plowing and the shovels cast the soil arching back leaving the topsoil on the surface. In our Final examination the Rotary Spader performed well even though having well-worn spades. Depth was adjusted deeper to allow spading down to over a foot in depth. New spades would add another six inches in depth. Over many seasons it’s expected that regular primary tillage with a rotary spader would incorporate any crop residue and green manure crops. This should increase the upper topsoil level humus while leaving the subsoil clay in place where it is. Soil compaction is a real problem on farms running horses or cattle on pastures. This spader works well to aerate and break up that compaction of heavy clay soils.

In Conclusion: The future plan for this Celli Rotary Spader is to continue our studies here conducting soil building and watching for improvement in crop growth and yields. If possible, I would like to report to SARE when S2S acquires a larger hp tractor to power this Celli Rotary Spader. A very solid machine, the Italians had used superior steel, engineering, and workmanship. I don't believe this unit would have survived this long after 20 years of steady use otherwise. I recommend the use of Rotary Spaders as a sustainable agriculture primary tillage tool based on these many years of observations.

Participation Summary
1 Farmers participating in research

Learning Outcomes

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

See "Materials and Methods" and "Results" sections of this report.

Project Outcomes

2 Farmers changed or adopted a practice
1 New working collaboration
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.