The Rural Voice, 2001-07, Page 407 Spontaneous
combustion and
hay fires a concern
By Harold K. House, P.Eng.
Beef & Dairy Structures and
Equipment Specialist
Clinton OMAFRA
Lives have been lost and hay
crops destroyed because of fires
caused by spontaneous combustion.
When the weather doesn't co-operate
many farmers try to store hay before
it is properly cured. If the hay crop is
put into the mow above 20 - 25 per
cent moisture content, spontaneous
combustion may occur.
A hay crop that is placed too wet
into a mow will rapidly heat. If the
mow is so large that heat loss is
restricted, the internal temperature
will rise. As the temperature rises
above 130° F (55°C), a chemical
reaction occurs and may sustain
itself. This reaction does not require
oxygen, but the flammable gases
produced are at a temperature above
their ignition point. These gases will
ignite when they,come in contact
with oxygen.
Check your hay regularly. If you
detect a slight caramel odour or a
distinct musty smell, chances are
your hay is heating.
What do you do? First of all,
make yourself a simple probe that
can be inserted into the hay mass to
check the temperature. A probe can
be made from a 10 -foot piece of
electrical tubing. Rivet a hardwood
pointed dowel to one end and drill
six half-inch diameter holes in the
tube just above the dowel. Drive the
probe into the hay mass and lower a
candy thermometer on a long string
into the probe. The thermometer
should be left for 10 minutes to
ensure an accurate reading.
Advice
CAUTION: Before entering the
mow. place long planks on top of the
hay. Do not attempt to walk on the
hay mass itself. Pockets may have
already burned out under the hay
surface. Always tie a rope around
your waist and have a second person
on the other end in a safe location to
pull you out should the surface of the
hay collapse into a tire pocket.
Extreme caution should be taken
when fighting a hay fire if hay has
been treated with chemical
preservatives. Hay treated with
preservatives containing exthoxyquin
and BHT (butylated hydroxytoluene)
will produce hydrogen cyanide gas at
around 240°F (115°C). This gas is
very deadly. Additives containing
primarily propionic acid do not
produce hydrogen cyanide during a
fire.
Many farmers sprinkle salt on hay
as it is stored, in an effort to prevent
hay fires. However, tests have shown
that salt has no effect on controlling
spontaneous combustion. Dry ice,
liquid nitrogen or carbon dioxide gas
pumped into the hay will help
prevent combustion by eliminating
the oxygen from the hay mass.
Spontaneous combustion is not an
accident. By following good storage
practices, not only will spontaneous
combustion be avoided, but a higher
quality of hay will be obtained.0
HADSS 2001 now
on the web
By Susan Weaver, Agriculture
and Agri -Food Canada,
Harrow and Hugh Martin,
OMAFRA, Guelph
Let your computer look at the
economics of your herbicide
treatment options by using
HADSS&trade the Herbicide
Watch for the following temperatures:
150°F (65°C)
160°F (71°C)
175°F (80°C)
°• Entering the Danger Zone
•° Danger!
°° CaII the Fire Department)
185°F (85°C) •' Hot spots and pockets may
be expected.
212°F (100°C) °° Critical!
Check temperature daily
Measure temperature every four
hours and inspect mow.
Wet hay down and remove from
bam.
Flames will likely develop when
heating hay comes in contact
with oxygen.
Temperature rise is rapid above
this point. Hay will almost
certainly ignite.
36 THE RURAL VOICE
Application Decision Support
System for corn and soybeans. The
2001 Ontario version of HADSS is
now available in several formats: on
the web, on CD-ROM, and a trial
version for Pocket PCs with the
Windows CE operating system. The
HADSS program is designed to help
producers, extension agents and farm
management consultants evaluate
alternative weed management
strategies.
HADSS was originally developed
at North Carolina State University
and has been modified for Ontario
conditions to reflect local weed
species, their impact on crop yield,
herbicides registered in Ontario,
regional herbicide prices, and growth
stage -specific product efficacies. It
provides information that can be used
for making weed control decisions,
such as estimates of the yield Toss a
weed could cause, and the economic
return from controlling weeds...
information that can be difficult to
estimate otherwise.
The web version of HADSS can
help with post -emergence weed
control decisions, including rescue
treatments. The user supplies
information on the number and types
of weeds present, weed size,
expected weed -free yield and
commodity price. The program
performs an economic comparison of
available treatments, including the
option of not spraying, and calculates
net return based on yield loss before
and after treatment minus the cost of
the product. HADSS on the web is
free at http://www.cropsci.ncsu.edu/
webhadss/. Just click on the Ontario
database and follow the prompts.
The CD-ROM version of HADSS
contains a number of additional
features. It evaluates soil -applied as
well as post emergence herbicide
treatments. It stores field records of
weed species and herbicide history,
and warns if the same herbicide
mode of action has been used for
three or more consecutive years to
reduce the risk of herbicide
resistance. It can rank the available
treatments by profit, by level of
expected weed control, or by
herbicide price, depending upon the
user's goal for the particular field.
The user can modify herbicide prices