The Burning Question: To burn or not to burn?

Every year this time of year, there is a big debate in the Grand Valley and I’m sure other parts of the state where burning and Agricultural burning takes place.  This article was going to be about residential area chickens but I recently saw article that was full of half-truths which has been eating at me.   Then I came upon an article in my husband’s Bugle magazine, which is produced by the Rocky Mountain Elk Foundation called, Return the Burn: Good Stewards.  It went on to say how beneficial burning is for elk habitat.  As many of you know or should know, always go with research based information.  That is why the Land Grant Universities like CSU exist. 

In history, burning was happening with the American Indians long before Europeans landed.  They used prescribed burns to clear areas for crops, to create meadows and pastures for wildlife, and helped keep the forest in a condition of succession of varying ages.  1 And of course, Mother Nature has been starting fires way before humans were around. 

So that brings us to today.  Many municipalities like Grand Junction do not allow burning within town, which makes sense.  Fire is usually not the answer in small spaces.  However, large growers of agronomic crops benefit from burning their fields and ditches because it makes it easier for irrigation to move through the fields.  The soils in western Colorado will not support the pivot irrigation of Eastern Colorado and the plains.   Converting over to other irrigation systems would be in the thousands of dollars of which most farmers cannot afford.   Burning can also help control other wintering pests like aphids on wheat which in turn allows less pesticides to be used.  The other option to burning ditches is to get in there with weed eaters.  Well, it is more economical, quieter and quicker to burn the ditches.  And yes, every year, someone that burns does not pay attention to the weather and it gets out of control.  That is the main reason there are burn permits to educate people about when and how they can burn and those that don’t have permits and start a fire can get in big trouble.   Of course safety of people, animals and property should also come first.

CSU The Semi-Arid Grasslands Research Center- Controlled Burn

Burning also helps control weeds that have already germinated or that are perennials.  Exposing plant tissue to a temperature of about 100°C for a split second (0.1 second) can result in cell membrane rupture, resulting in loss of water and plant death. Thus, the weeds do not need to be burned up, but rather just scorched.  Flaming works best on very young weeds. 2  The farmers that burn will also tell you that it decreases the number of times they need to get into the field thus fewer times of stirring up more dust particulates that go into the air.  As far as microbes and the health of the soil, the big factors are the duration and the intensity of the heat and how much organic matter exists.  “While high intensity fires tend to decrease site productivity, low intensity fires can increase site productivity (Carter and Foster 2003).” 3 Most information on this topic is from forestry studies, so what is happening in a farm field would be a good study.  Since these fires are quick moving, any damage should be decreased compared to forest fires.

There is a new way of heating organic matter at a very high heat without the presence of oxygen to produce bio-char and bio-oils.  This process is called Pyrolosis.  This bio-char, which is charcoal like, is supposed to help with soil amendment, with forest reclamation, carbon storing in soils.  http://extension.colostate.edu/topic-areas/agriculture/biochar-in-colorado-0-509/ Why I have made the jump to this is, I think it might be a viable process to get rid of fruit tree trimmings that are infected with Cytospora fungus or Fire Blight bacteria.  http://extension.colostate.edu/topic-areas/yard-garden/fire-blight-2-907/   The only way to get rid of these two diseases is to burn or to bury.  So fire can help reduce the spread of disease.

Cytospora Canker on Peach tree, SLCarter

Now I am not saying that more people should burn, my message here is that it is another tool that should be considered for certain situations like weed control, water movement...  And I believe people need to be very responsible when burning and get the appropriate education and permits before lighting the torch.  I would rather put up with a little more smoke and decrease the number of pesticides than not.  Plus, our farmers need our support.  Remember, there are normally reasons for processes in Agriculture and there are always two sides to a story.  That’s mine for today.  Here’s to spring and a good growing season.  Susan Carter, CSU Extension Horticulture Agent.

Footnotes:

11.       Thomas M. Bonnicksen, M. Kat Anderson, Henry T. Lewis, Charles E. Kay, and Ruthann Knudson. 1999. Native American influences on the development of forest ecosystems

22.        CSU CMG Garden Note #351, Weed Management

33.       Fire Effect on Soil, Fire Effects on Soil Nutrients, modified from Forest Encyclopedia Network webpages. http://www2.nau.edu/~gaud/bio300w/frsl.htm