Aeration Tillage Effects on Hay Yield and Soil Health in Clay Soils

2014 Annual Report for ONE14-202

Project Type: Partnership
Funds awarded in 2014: $14,986.00
Projected End Date: 12/31/2017
Region: Northeast
State: Vermont
Project Leader:
Jeffrey Carter
UVM Extension
Rico Balzano
Little Lake Orchard

Aeration Tillage Effects on Hay Yield and Soil Health in Clay Soils


Compaction causing anaerobic conditions and poor water infiltration is the number one reason hay field productivity declines over time. The strategy proposed by the Champlain Valley Crops, Soils, and Pasture Team, in conjunction with partnering farmers, to alleviate surface compaction was to use aerator machines to poke slots into the soil to allow greater air and water infiltration.

The strategy was implemented on two farms with varying degrees of success. The first partnering farmer, Doug Gould, aerated alternating strips across two separate hay fields he spring and after the first two hay cuts. Also, he applied two different rates of fertilizer across the two treatments. He then decided to aerate this fall (2014) instead of early next spring due to potential damage to the hay crop. Henry Lawton split his hay field into three blocks and aerated one block with a newly designed double axel aerator, another block with a conventional single axel aerator, and left the third block unaerated as the control. He did this in the spring and after the first two cuts of hay.

Objectives/Performance Targets

Two trials were conducted on farms in Addison County Vermont to test the feasibility of compaction relief using aerator machines on permanent hay ground. The aerator machine used were farmer owned machines: Doug Gould owns an 11 foot Gen-Til, Henry Lawton owns a 20 foot Aerway, and Heustis Farm Supply owns 10 foot double-axel Aerway. The use of these aerator machines enabled us to conduct the trial.

Doug Gould aerated strips 13 ft. wide (to accommodate his 11 ft. Gen-Til machine). The aerated strips alternated with non-aerated strips across the field. The field was then split between two different fertilizer treatments. The higher rate (also known as the UVM rate from the proposal) was 1.5 times the low rate (also known as the farmer rate from the proposal). The fertilizer was 30-10-10. Forage sample were sent out for analysis for each of the three cuts of hay from both farms from each of the treatments. This totaled 12 samples from Doug Gould and six samples from Henry Lawton. In the spring of 2014, preliminary soil tests were taken on both farms for all treatments, and in the fall of 2014, the Cornell Soil Health Test was done for the two treatments on the Doug Gould farm. Also, soil samples were sent out for the Haney soil test, which is based on the Solvita CO2 test. This analysis will provide a comparison of soil health benchmarks as well as a comparison to the Cornell Soil Health Test.


November 2013: First pass with aerators on trial plots at Doug Gould’s.

April 2014: Aerator machines used on all plots on both farms. Species mix evaluated at both sites. Fertilizer applied on plots at Doug Gould’s. Soil tests (UVM) done to determine field variability. 

May 2014: Yield data and forage analysis measured in each plot.

June 2014: Aerator machines used on all plots (following first cut). Fertilizer applied at Doug Gould’s.

August 2014: Yield data and forage analysis measured in each plot.

August 2014: Fourth pass with aerators on all plots (following second cut).

September 2014: Yield data and forage analysis measured in each plot

September 2014: Fifth pass with aerators on all plots (following third cut).

October 2014: Soil health sampling done with Cornell Soil Health Test and Haney Soil Health Test (Solvita CO2 analysis).

Impacts and Contributions/Outcomes

Yields were measured in bale counts on both farms. No significant difference was found on either farm in 2014. In fact, Doug Gould found that the aerated plots yielded slightly lower for the first cut. He thinks this may have been due to the aerator machine damaging the growing hay in the early spring. Also, Doug’s fields have a higher percentage of alfalfa which may be more sensitive to early spring traffic than a mostly grass hay field. Also, due to the narrow strips, Doug had a difficult time raking the hay from just the strip into a windrow to be baled. For these reasons, he will change the configuration of the trial on his farm for next year. He will split his fields into four blocks, aerating two blocks and not aerating the other two blocks. The separate fertilizer rates will be applied to each set, splitting the field as discussed in the proposal. Using this new strategy may provide a more efficient method for measuring yields

The field trial operated by Henry Lawton used this block method and was able to keep the windrows separate, therefore getting a more accurate bale count. Another factor at the Henry Lawton site is that the field being used for the trial is being transitioned to organic certification, and no fertilizer is being applied until the transition is complete and chicken manure can be applied and organic prices for the hay can justify the cost. The species mix is also mostly grass, with less than 20% clover. While the aeration may have long term benefits, those benefits may not be realized in the early years of the aeration treatment; yields may be more influenced by the species mix and fertilizer program.


Henry Lawton

Farm Owner
5235 Lake Street
Bridport, VT 05734
Office Phone: 8027582382
Doug Gould
Farm Owner
2072 Nortontown Road
Addison, VT 05491
Office Phone: 8027592509