The CFS is concerned about the large volume of grass and crop growth across SA following a wet spring.
The Yumali Fire (now controlled) burnt 4,900 hectares in just four hours on Thursday 19 November.
CFS State Duty Commander Yvette Dowling said when fires enter crops or heavily grassed areas, they burn incredibly quickly.
"The fire travelled with such speed that it was not safe for us to put our trucks in front of it in an attempt to extinguish," CFS State Duty Commander Yvette Dowling said.
"The fire burned with such ferocity that at times it was difficult for our firebombers to attack the flames."
The CFS airfleet completed 48 drops of firefighting products onto the fire, totalling more than 110,000 litres of product dropped from above.
During the fire two people were injured when a CFS 4WD and a private vehicle had a head on collision. All occupants were cleared of major injuries.
One house and one shed were destroyed in the blaze.
The fire was sparked by SA Power Infrastructure.
There have been a number of haystacks producing smoke from the fire.
In the Upper South East, 2,300 hectares were burned in the Deepwater bushfire which started on 15 November and has since been contained. There have been reports of smouldering tree stumps and logs within the fireground.
The CFS urges residents to clean up their properties now, and have a Bushfire Survival Plan.
More details on how to create a Bushfire Survival Plan can be found at cfs.sa.gov.au.
Photo of Candadair CL-415 water bomber in Canada, CC by Maarten Visser - Wikimedia Commons