Fire and regenerative rangeland management

Fire is a management tool and, like a hammer, it can have good or bad consequences, depending on how and when it is used. This requires careful consideration of a farm’s conditions, writes Colin Nott, a regenerative agricultural consultant based in Namibia.

- Colin Nott

The impact that fire has on a livestock enterprise in terms of profit, forage production, biodiversity and the soil microbiome depends on a number of factors. These include, amongst others, the perennial basal cover of the soil, the amount of bare ground, the ratio of perennial to annual grasses, the density of the bush and the soil type.

Other factors focus on the fire itself. Is it ahead or rear fire? What are the environmental conditions, such as wind speed, humidity, and fuel load, during the fire? Is it a cool, early season burn (when grass plants just start going dormant) or a hot, late-season burn? All of these will determine the impact of the fire.

DIFFERENT TYPES OF FIRE

Fire can never be applied as a single tool; it always occurs within a management context before and after the fire. Important factors playing a key role in this respect include grazing recovery periods and animal impact. For example, early burning followed by continual selective grazing will probably result in excellent animal performance, but it will bring about overgrazing of plants, and the resource base is therefore likely to decline over time. Repeated late, hot fires may kill mature trees in a woodland, and in the absence of well-managed ruminants may lead to a decline in the productivity of the resource base. Fire used repeatedly in higher-rainfall areas with a predominance of perennial grasses may remain productive and profitable if recovery periods are planned for.