Prescribed Fires: A Farmer's Introduction to Controlled Burning

Jesus Quintana

Global Expert in Sustainable Agriculture and Natural Resource Management

6 min read
12/12/2024
Prescribed Fires: A Farmer's Introduction to Controlled Burning

Prescribed Fires 101: A Farmer's Guide to Controlled Burning

Introduction

Prescribed burning (also known as controlled burns or prescribed fires) is the practice of intentionally setting fire to a predetermined area under specific environmental conditions to achieve a desired outcome. This technique is a beneficial fire management practice used by practitioners worldwide to meet multiple land management objectives, including reducing wildfire hazards, promoting biodiversity, and managing vegetation for wildlife and human benefits (Smithwick et al., 2024).

Historically, fire has been used by various cultures as a land management tool. Traditional field burning has long been used to enhance pasture quality and manage upland vegetation. Pastoralists and indigenous communities, as well as many other agricultural societies and rural peoples, have traditionally employed fire to stimulate new growth for improving grazing, as well as to promote ecological balance, clear pathways, attract game, and manage vegetation. These controlled burns were integral to maintaining biodiversity and preventing larger, uncontrolled wildfires​ (FAO, 2024). 

Fire is still the most economical method for improving forage for domestic and wild animals and increasing livestock production, among other benefits. Yet, it can also damage or destroy homes, food, and natural resources and pollute the air. Moreover, using fire to prepare fields (management of crop residues), reduce pests and diseases, and improve forage results in disasters when these fires escape.

To mitigate these risks, the use of fire in agriculture faces increasing regulatory limitations due mostly to environmental concerns, including its impact on forests, wildlife, and nesting birds and its greenhouse gas (GHG) emissions. In many countries, governments have been passing laws that promote integrated fire management, regulating prescribed burning, and imposing seasonal restrictions or total bans on burning to lessen or avoid these adverse effects​ on ecosystems, public health, and welfare. 

Advantages and challenges of prescribed fires

Prescribed fires, or the systematic application of burning to meet specific land management needs or goals, incorporate one of the few naturally occurring soil and land management tools. Used properly by trained practitioners, prescribed fires can offer a safe, inexpensive, and efficient way to enhance the productivity and beauty of a variety of landscapes.

Landowners and managers, municipalities, logging, agricultural and livestock industries, and conservation professionals all increasingly recognize that setting prescribed fires may reduce the devastating effects of wildfire, control invasive brush and weeds, improve livestock range and health, maintain wildlife habitat, control parasites, manage forest lands, remove hazardous fuel in the wildland-urban interface, and create residential buffer zones.

Controlled burns can also enhance soil fertility by returning nutrients to the ground and helping manage invasive species. They also play a critical role in reducing the fuel load in forests, lowering the risk of catastrophic wildfires (Alcañiz et al., 2017). However, this method also has some drawbacks, such as the potential for burns to escape control, leading to unintended damage, and the release of significant amounts of carbon dioxide and other GHGs, contributing to air pollution and climate change.

To mitigate these risks, it is essential to implement robust fire management plans that consider factors such as weather conditions, fuel moisture, and topography. Public education and outreach programs can also help raise awareness about the benefits and risks of prescribed fire.

Fire as a tool for sustainable agriculture 

Comprehensive fire management, or integrated fire management (IFM), is a strategic approach that balances the risks and benefits of fire to protect landscapes, resources, and communities. By integrating prescribed fire into land management practices, IFM can contribute to sustainable agriculture, reduce wildfire risk, and enhance biodiversity.

IFM programs typically encompass two key components (AGIF, 2023):

  1. Prescribed fire integration: This involves the planned use of fire, both natural and human-caused, to achieve specific land management objectives, such as reducing fuel loads, improving pasture quality, and controlling invasive species.
  2. Community engagement: IFM programs emphasize the importance of involving local communities and land users in fire management decision-making and implementation. By working together, communities can develop effective strategies to reduce wildfire risk and promote sustainable land use.

Prescribed burning under IFM involves careful planning, consultation, and monitoring, underpinned by rigorous approvals processes, which usually take these steps (DBCA, 2024):

  • Determining what vegetation needs to be burnt and what needs to be left unburnt (mosaic), the desired fire intensity, and the season.
  • Considering the history and variety of past fire events over the landscape.
  • Studying and measuring the quantity, arrangement, and moisture content of fuels.
  • Determining, monitoring,g and forecasting the right weather conditions (wind, humidity) for igniting a burn using knowledge about fire behavior.
  • Determining the best time of day to ignite a burn in a specified pattern and sequence to achieve the desired outcomes and to prevent fire from escaping.
  • Monitoring the results of a burn to determine how well the operation met the objectives set for the burn.
  • Using knowledge gained and lessons learned to improve future prescribed burning operations.

Alternative practices to burning

Although prescribed burning has many benefits when applied correctly, there are cases in which it may not be an option: 

  • Difficulty obtaining burning permits.
  • Concerns about liability.
  • Potential effects on the growth and survival of crop trees.
  • Limited burning days.
  • Costs of applying, controlling, and monitoring burns.

In those cases, there exist alternatives to fire use, such as mechanical thinning, grazing and agroforestry practices, which can be particularly beneficial in regions where environmental conservation, air quality and climate goals are paramount.

Some alternatives to prescribed fires include: 

  • Mechanical treatments: These include mowing, mulching, timber harvesting, hand felling, and roller/drum chopping. 
  • Herbicidal treatments used to target woody and herbaceous plants that create shade. Herbicides can be a cost-effective alternative to prescribed burning, especially when the boundaries of application are well-defined.
  • Raking after mowing, which can promote desirable herbaceous plant species while being less damaging to species that are sensitive to intense heat. 
  • Grazing: This method may require the installation of infrastructure like fences, and animals may be susceptible to poisonous plants. 

Conclusions

When used responsibly, prescribed fire is a powerful tool for land and soil management. It mimics natural fire cycles, promoting biodiversity, reducing wildfire risk, and enhancing wildlife habitat. However, fire must be treated with respect.

Careful planning, consultation, and adherence to Integrated Fire Management (IFM) principles are crucial for successful prescribed burns. IFM emphasizes rigorous approval processes, meticulous planning based on weather, fuel load, and desired outcomes, and thorough monitoring after the burn.

While prescribed fire is not always an option, alternative methods like mechanical thinning or controlled grazing can achieve similar goals, particularly in areas prioritizing environmental conservation and air quality.

Ultimately, fire, employed responsibly, can be a force for good in the natural environment, ensuring a healthy and sustainable future.

References

Further reading

Agricultural Residues (Biomass) and their Management

What is (Crop) Residue Management?

Risk Management Approaches in Agriculture

Shifting Cultivation: A Dynamic System for Resource Management

Jesus Quintana
Global Expert in Sustainable Agriculture and Natural Resource Management

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