Effects of tedder setting on swath spread and ground cover

Jessica Williamson, Hay and Forage Specialist, AGCO

Making hay is often a time-sensitive endeavor where hours count and balancing hay quality and machine efficiency is imperative.  Although hay machines have a standard recommended PTO and ground speed for operation, farmers and operators sometimes do not follow those recommendations due to time constraints or other personal convictions.  

Tedding can be a useful tool prior to raking hay to slow respiration, increase dry down, and assist in uniform drying across the field, especially in low-lying and wet areas of the field.

In collaboration with Cornell University, Massey Ferguson conducted a trial in Canton, USA on a second cutting mixed cool-season perennial grass. The objective of this study was to determine the effect of tedder ground speed and PTO RPM speed on swath spread and ground cover. Massey Ferguson tedder was operated at 2 different ground speeds by 2 different PTO RPM speeds.


   PTO RPM x Ground Speed   


540 RPM x 6.5 km/h

440 RPM x 6.5 km/h

540 RPM x 16 Km/h

440 RPM x 16 Km/h

Due to rain following tedding, forage quality measurements were not taken in this trial. 


Width of Spread

Tedding at 540 PTO RPM resulted in less swath width than a PTO RPM of 440. The greater the width of spread of the swath, the faster the dry down of forage will occur, reducing respiration and potentially increasing forage quality (Figure 1). 

Figure 1. Width that forage was sprad across various PTO RPM x Km/h treatments


Ground Cover

The greatest amount of ground cover occurred at the 540 RPM x 6.5 Km/h treatment, followed by 440 RPM x 6.5 Km/h, which both surpassed the amount of ground cover that resulted from the 16 Km/h treatments (Figure 2).  This indicates that regardless of PTO RPM, traveling at a speed of 6.5 Km/h may have a greater effect on sufficient ground cover during tedding than traveling at a high rate of speed.  The greater the percent ground cover, the more evenly the hay can be exposed to sunlight and air flow, increasing the rate of dry down and reducing respiration, potentially leading to improved forage quality.



Figure 2. Percent of ground that was covered across various PTO RPM x Km/h treatments


Tedded Swath Height

Traveling at 6.5 km/h yielded the swath with the greatest height regardless of PTO RPM speed, while traveling at 16 km/h resulted in a lower height in tedded swath. Greater swath height while maximizing ground cover can synergistically work together to dry down hay fastest and most efficiently.  Comparatively speaking, swath height variability x treatment did not lend to significant results across various treatments – no conclusive evidence can be determined from this trial that ground speed or PTO RPM speed effects tedded swath height variability 




Figure 3 and 4. Swath average height (cm) and height variability (cm) after tedding at various PTO RPM x ground speeds

Harvest efficiency can be optimized by following machine recommendations and helping to ensure forage is harvested efficiently and optimally.  According to this trial, a 440 PTO RPM resulted in the greatest width of spread of the tedded swath, potentially leading to faster dry down and stopping respiration faster – both leading to greater overall forage quality. Traveling at 6.5 km/h resulted in a greater percentage of ground cover compared to traveling at 16 Km/h – potentially leading to faster dry down and greater forage quality.

  • Tedder PTO RPM in recommended range of 440-450
  • Ground speed at 6.5 - 8 Km/h


Agronomist Bio

Dr. Jessica Williamson is the hay and forage specialist for AGCO. Jessica’s expertise is in forage quality, management and production, as well as ruminant nutrition and the plant-animal interaction. Jessica is responsible for designing and conducting field tests on hay and forage equipment; educating AGCO personnel and customers on forage management, production and livestock nutrition; and working with the Green Harvest team on ongoing forage projects.

Jessica holds a Bachelor of Science degree in animal science from Morehead State University (Morehead, Ky.); a Master of Science degree in animal science (ruminant nutrition) from the University of Arkansas (Fayetteville, Ark.); and a Ph.D. in plant and soil science (forage agronomy) from the University of Kentucky (Lexington, Ky.). Jessica is originally from a cow-calf operation in western Maryland.

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