From "Managing Michigan's Wildlife: A landowner's guide"
There are 4 basic burn techniques used in the prescribed burning of grasslands. These four techniques include:
- back fire
- parallel (flank) fire
- perimeter (ring) fire
- strip head fire
Each method has strengths and weaknesses depending on the weather conditions, size of the area, and expertise of the individuals conducting the fire. Special considerations when conducting the burn include power lines, telephone lines, and oil or gas lines.
A backfire is used downwind of the burn site. This is most often the coolest and safest fire. However, it is slower burning and therefore takes longer to finish. The fire is ignited on the downwind side of the fuel and slowly burns into the field against the wind, expanding the firebreak. This burn technique is often used in conjunction with other burn methods.
A strip head fire burns slightly faster than a backfire, is relatively safe, and works well for burning rectangular or odd shaped parcels. It is also cost-effective. A series of strips are lit, starting at the downwind side of the site. Ideal when burning with a limited number of personnel.
A parallel or flank fire burns hotter and faster than a strip fire or backfire. It works well on square or circular parcels. A fire is ignited on the sides of the burn site parallel to the wind direction at the same time or soon after a backfire is lit. The people igniting the fires on either side should keep continuously in touch by 2 way radio.
A perimeter fire is not only one of the quickest burn methods, but also creates a hotter fire than those listed above. Since this type of burn technique develops a hotter and faster moving fire, which can be harder to control, it must be handled carefully. This method starts with a backfire, followed by lighting the flanks, and finished by lighting the upwind side of the burn site called the head of the site. This headfire will move rapidly towards the flanks and backfire.
Remember that when choosing a burn technique, your level of experience with burning and that of your burn crew should be a major factor in your choice.