“Grazing capacity” is not the most click-bait phrase that one would find on the internet. It probably comes somewhere between “Donald Trump’s hair” and “exciting new developments in toaster manufacturing” in public interest.

But for millions of square kilometres of the earth’s surface, grazing capacity is critically important. Grazing capacity, very simply, is the number of animals that can graze on a certain area of land for a certain period of time, generally without dying of starvation in the process, and without denuding the soil of every blade of grass.

The concept of grazing capacity, therefore, implies a balancing act between the needs of the veld and the needs of the animal. The veld does usually need a certain amount of grazing, but too much and the perennial, palatable grasses start to disappear and unpalatable grasses and bare soil take their place. Weeds start to encroach, erosion gullies appear and rainwater no longer infiltrates into the topsoil to feed the roots of the remaining plants. Overgrazing, in other words, causing grazing capacity to decline in the long term, and nobody benefits. Yet we still struggle to actually measure grazing capacity.

Agricultural colleges have been teaching trainee farmers a precise, powerful, repeatable and completely inappropriate method of veld monitoring for decades.

One of the first things any serious livestock farmer will tell you is that they are not farming livestock, they’re farming grass.

The grass is the primary crop, converted into cash via the medium of a cow or a sheep or a springbok. But farming wild grass – veld in southern Africa - is not like farming other crops. The farmer has very little control over productivity. He cannot plough the fields and plant precisely the variety of crop that he wants, while carefully weeding out the undesirable ones. He has to deal with the normal vagaries of nature. And finally, he has the grazing itself, which affects the composition of different grasses and weeds in ways which, after more than a century of research, we barely have a handle on.

Simple, prescriptive formulae for how to manage nature don’t work in the long run. Farmers need to read the subtle signs of the veld and adapt, constantly tweaking their management, week to week, month to month and year after year. They need to decide when to put cows and calves into the veld based not on the calendar but on the grass itself. They need to move their animals following the signals of the veld, not the traditions of their fathers. And they need to decide when and where to burn following the same cues.