Andrew Hollman, Dr. Brian Horgan, & Sam Bauer, University of Minnesota
When given lemons make lemonade. When given an ice sheet, conduct an ice melt
study. On January 31 at the Hancock
Turfgrass Research Center (HTRC) at MSU we conducted an ice melting study in
cooperation with Dr. Brian Horgan, Andrew Hollman, and Sam Bauer from the
University of Minnesota. We tested 20
products for their ability to melt ice. Conditions
during our treatment window which began at approximately 11 am and concluded at
5:30 pm had temperatures hovering around 25 °F and
constant cloud cover. The treatments can
be broken down into three general categories:
Standard Chemcials/Salts (all application rates 28 lbs./1000
ft.2)
1. Calcium chloride
2. Sodium chloride
3. Potassium chloride
4. Magnesium chloride
‘Safer’ ice melt products (all application rates 28
lbs./1000 ft.2)
5. Calcium magnesium acetate (CMA)
6. Sodium acetate (NAAC)
7. Enviro Melt (carbonyl diamide/urea)
8. Safe Paws (modified amide/glycol admixture)
9. Paw Thaw (CMA and fertilizer)
10. Tenderfoot Ice Melter (urea and DeFrost)
11. Ammonium sulfate.
Solar Absorption Products (dark colored)
12. Milorganite greens grade (56 lbs./1000 ft.2)
13. Sustane greens grade (40 lbs./1000 ft.2)
14. Top Cut biosolids SGN 90 (53 lbs./1000 ft.2)
15. Top Cut SGN 200 (53 lbs./1000 ft.2)
16. Top Cut + DeFrost SGN 200 (53 lbs./1000 ft.2)
17. BioDac + DeFrost SGN 200 (47 lbs./1000 ft.2)
18. BioDac + DeFrost + Colorant SGN200 (47 lbs./1000 ft.2)
19. Eon 75 humic acid (47 lbs./1000 ft.2)
20. Black sand (100 lbs./1000 ft.2)
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| Treatments on ice sheet at MSU. |
We recorded surface ice temperatures prior to treatment
application and at intervals following applications using an infrared
temperature sensor. We rated ice melt
based on observation of standing water on the plots on a scale from 1-5 with 1
= no visible melt, and 5 = visible standing water.
Surface temperatures prior to treatment application were
very similar to air temperatures 25-26 °F. One hour after treatment application the
treatments were separated into two groups, the standard salts and safer ice
melt products vs. the solar absorption products. The solar absorption products with their dark
coloration had surface ice temperatures of 35-37 °F
whereas the salts and safer treatments had surface ice temperatures of 27-31 °F. Treatments
were still significantly different at 4.5 hours after treatment application
although the temperatures for the solar absorption products declined to 30-32 °F, most likely due to the sun setting.
There were also differences in visible melt from the
treatments. The following treatments
produced the most visible melt: Milorganite, Sustane, Top Cut biosolids SGN 90,
Eon 75 humic acid, and black sand. The
standard salts and safer ice melt treatments produced very little visible ice
melt.
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| Solar absorption products had the greatest melting. |
The standard salts were the only
treatments we observed that were able to penetrate through the 2 inch ice sheet
so they could be effective in facilitating gas exchange with the surface but of
course there is the risk of turf burning from the salt properties of these
treatments.
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| Calcium chloride melted holes all the way to the turf surface. |
Overall, even though
temperatures were below freezing and cloud cover persisted the solar absorption
treatments were effective at melting the ice surface but were unable to melt to
the surface given our 2 inch ice sheet. We are planning to replicate this trial again this coming
week at both MSU and Minnesota when temperatures are forecast to be above freezing. We will also be assessing turfgrass
phytotoxicity from the treatments this spring.
Helping the Melt
Next week most areas of Michigan are forecast to have
temperatures above freezing and possibly into the mid 40’s in combination with
rain. Many superintendents have been
attempting to clear greens down to the ice layer to facilitate melting. Keep in mind that if this melt occurs there
is going to be a tremendous amount of water that will be moving off
greens. Ensuring the water can exit the
greens will be critical to try and prevent water backing up onto the green and
refreezing if temperatures drop below freezing at night. Ultimately Mother Nature is going to dictate
whether or not our Poa annua putting
greens have survived the ice sheet and the pending melting and freezing in
the next month.