Evaluation of Ventilation Systems under Winter Covers to Prevent Injury

from Anoxia on Annual Bluegrass Putting Greens

Progress Report to:

Canadian Turfgrass Research Foundation

July 2014

Research Team: Jim Ross, Darrell Tompkins, Ken Fry, Katie Dodson and Mark Anderson.

Prairie Turfgrass Research Centre

Olds College

Research Initiated Since Last Report

The Glendale Study

This study was initiated during the winter of 2011-12 with the following objectives.

  1. Develop a cover system that would prevent winter injury from desiccation, low temperature, and ice cover (anoxia).
  2. Develop a system to monitor temperature and gas concentrations under this cover system.
  3. Develop a system to continually ventilate air under the covers in order to prevent gas concentration fluctuations.

This was the third and final year of this field trial that was conducted at the Glendale Golf and Country Club in Edmonton, Alberta. A final report will be written and submitted for the September 15 reporting period. A large amount of data has been collected over the duration of this study and in-depth analysis of this information is necessary before the report can be completed.

Covers were installed in early November one day prior to permanent snow cover. Gas concentrations and temperatures under the covers were collected on a weekly basis (usually Wednesday) for the duration of the trial. The final data collection was completed in early April.

Thresholds of 8% oxygen and 8% carbon dioxide were established as a point where supplemental ventilation would be undertaken by the staff. Either oxygen levels below 8% or carbon dioxide levels above 8% would be the determining values for intervention. The number of ventilations was recorded throughout the winter months.

The Olds Study

Golf Superintendents need to know what lethal gas concentrations are and how long plants can endure these lethal concentrations, if at all. At this point, recommendations to Superintendents are to ventilate their greens when O2 levels fall below 8%. However, these recommendations may be too cautious and plants may be able to withstand far lower O2 concentrations and for longer periods of time.

One of the main objectives of this study was to conduct a field experiment at Olds College to determine gas concentration values that would cause turf injury. However, we were unable to obtain anoxic conditions under the covers in the field due to their small size. We speculated that there was an edge effect under the small covers where some air circulation would occur and as a result gases never got to a lethal concentration.

Due to the limitations of the small-plot work, we have initiated a pilot study in the lab. The overall objective of determining action thresholds remains the same but now we have moved the study into a controlled environment. We filled 1.9 L Mason jars with various concentrations of O2 and CO2 and cores of ABG greens height turf. There are many factors involved in ensuring a successful study so the current pilot study was designed to perfect the methodology prior to the initiation of the first full year of the trial in October 2014.

Progress to Date

The Glendale Study

  • Third and final year of data has been collected from the various covering systems
  • Data has been entered into the computer and analysis of variance has been conducted
  • Tables of the data have been developed
  • Meetings have taken place to review individual data points to determine changes to the statistical analysis. There appeared to be a few periods where gas levels changed more than 500%in one week and then after a few weeks went back to the previous levels. We speculated that the gas extraction tubes became clogged which caused the fluctuations.
  • Currently descriptive statistics are being run to determine how to deal with the anomaly that was found in the 2012-2013 data.

The Olds Chamber Study

  • Mason jars were hermetically sealed by installing bulkhead unions and luer fittings and then sealing with silicone. Jars held a vacuum for greater than three weeks.
  • Non-hardened plugs of annual bluegrass were collected from the field and placed in the jars.
  • Two gases mixtures were obtained (5% oxygen 10% carbon dioxide and 0% oxygen and 15% carbon dioxide) and were released into the jars.
  • Samples were collected and gas concentrations were determined by using the Portable Multi-Gas Detector (RKI Instruments Inc. Model: Eagle 71-0028RK). This portion of the methodology seemed to work well.
  • Once we obtain more gases the pilot study will continue.
  • The growth chamber was tested to determine if it could hold a temperature of 0.5oC for an extended period of time.
  • The first year of the study will begin in late October when we collect field hardened plant material because we have found through previous research that field-hardened turf provides the most reliable data.

Results

The Glendale Study

  • Once again, the treated greens (16 in total) came through the winter without any winter damage. In fact, when viewed in mid-June it was obvious that these greens were far ahead of others in the Edmonton area.
  • The ventilation system that continually circulates air under the covers, once again, appears to be the best of the systems tested.

The Olds Chamber Study

  • The sealing of the Mason jars appears to be effective.
  • The method for collecting and detecting gases with the meter appears to work well.
  • The growth chamber appears to work properly and holds a consistent temperature without freezing.