Evaluation of the effects of aerators on alfalfa stands

2011 Annual Report for ONE11-148

Project Type: Partnership
Funds awarded in 2011: $14,992.00
Projected End Date: 12/31/2013
Region: Northeast
State: Vermont
Project Leader:

Evaluation of the effects of aerators on alfalfa stands


Project planning meetings took place immediately upon grant award with project leaders and UVM Extension System professionals to discuss details of project including data collection, analysis, size and structure of research plots, and coordination.

Jennifer Alexander met individually with each farmer to discuss the project details. The Russo Farm had to drop out of the project before this award was granted due to management changes and the Clarke Farm had to withdraw in May when a large tract of rental land was not renewed and the farm was not going to have the test land in alfalfa for the 3 years needed. Clif-Dee Farm (Cliff Cressy Jr) in Florence and Fern Hill Farm (Steve Bromley) in Wallingford were selected to replace them. In the beginning of May, Jennifer and intern Brandi Bunkley oversaw the aeration and staked out plots on Ruane, Cressy and Harvey Farm. Unfortunately, due to the timing of when the Clarke farm withdrew and the growth of the alfalfa at the Bromley farm, the Bromley, the alfalfa was over 10 inches tall and the farmer did not want to drive on the field at that time. That plot was aerated and staked after 2nd cut. A subsection, sized 3ft by 3ft, of each plot was randomly selected for alfalfa crow counts. Crown counts took place after aeration and the number of crowns impacted by the aerator blades was noted. Diagrams of layouts on each farm are attached in Appendix A.
All research plots were on alfalfa seeded hayfields that were a minimum fifty percent alfalfa with one plot being newly seeded pure alfalfa stand, another was newly seeded with fescue, the third was a 2 year old stand of pure alfalfa and the fourth was a mature stand that was inter-seeded with timothy in spring of 2010. The plots are side-by-side which allow for an experimental and a control area and aeration was completed by the 8’ 9” GenTil unit.

The following tests were conducted during the 2011 growing/research season:

Cornell Soil Health test
Manure nutrient test
Plots were observed after each harvest and growth was monitored throughout the growing season.
Digital photograph was done during aeration and throughout the growing season

Aerate ControlStrip Aerate ControlStrip Aerate
20ft x 10ft 20ft x 10ft 20ft x 10ft 20ft x 10ft 20ft x 10ft

Objectives/Performance Targets

  • Objectives/Performance Targets
    • Objectives/Performance Targets
    1. Evaluate use of aerators on alfalfa and its effects on alfalfa where the taproot is more susceptible to damage on the farm scale level.
    • Four farms participated. The above data was collected and is currently being evaluated. While further evaluation needs to occur, the following anecdotal information has been shared with farmers: Aeration does not appear to harm alfalfa stands through the growing season.


The research and data collection part of the project went mostly according to plan. Alfalfa on these farms did not seem to be negatively affected by aeration and that crown counts would be conducted in the spring to estimate winterkill within the plots. The aeration was done when the plants were less than 5” tall.

Impacts and Contributions/Outcomes

Impacts and Contributions/Outcomes
Most farmers were still rolling their eyes at the thought of aerating alfalfa and this practice may be a hard sell even if there are no adverse effects. This summer posed a challenge to most farmers as they were either facing drought or wet conditions which made harvesting a challenge. Tropical Storm Irene was detrimental to the Harvey Farm plot. When the flood waters receded, the Otter Creek left a silt/sand covering on the field ranging from 4 inches to 3 feet deep. In the test plot area less than 10% of the alfalfa plants survived. Because the field will have to be replanted, the Harvey Farm is no longer in the trials and the research will continue on the remaining three farms.


Steve Bromley

47 Creek Rd.
Wallingford, VT 05773
Office Phone: 8024462285
Dr. Heather Darby

Extension Agronomist
UVM Extension System
278 S. Main St.
St. Albans, VT 05478
Office Phone: 8025246501
Matt Harvey

303 W. Creek Rd.
Florence, VT 05744
Office Phone: 8025580956
Cash Ruane

4528 Creek Rd.
Clarendon, VT 05777
Office Phone: 8027736837
Cliff Cressy

3926 Whipple Hollow Rd
Florence, VT 05744
Office Phone: 8024385036