Carrying Capacity South Africa: How to Calculate It for Your Farm

The carrying capacity figure that came with your farm — the one on the deed, or the one the previous owner mentioned at the gate — is almost certainly wrong for your current conditions. It was accurate when it was first calculated, the grassland scientists who calculated the benchmarks did very good work. But if the veld has changed, the number has changed with it.

Carrying capacity is not a fixed property of a piece of land. It is a function of veld condition at a given point in time and a function of actual rainfall, managed in a way that improves the effectiveness of that rainfall. The number that matters is the one you calculate yourself, based on what your grazing and rainfall records tell you about what is happening in the veld in front of you.

What Carrying Capacity Actually Means

Carrying capacity is the maximum number of animals that a given piece of land can support without causing long-term deterioration to the veld and soil. In South African practice it is expressed in Large Stock Units (LSU) per hectare — or more usefully, in hectares per LSU.

One LSU is defined as a 450 kg bovine animal, or the metabolic equivalent in other species. A mature Bonsmara cow at 450 kg is 1 LSU. A mature Nguni cow at 320 kg is approximately 0.7 LSU. Mixed flocks of small stock are typically calculated at 0.12 – 0.14 LSU per animal.

Why Regional Benchmarks Mislead

Regional carrying capacity benchmarks are calculated from long-term average rainfall data and assume average veld condition. They rarely reflect your specific situation. Here is why:

• They do not account for current veld condition. Degraded veld carries fewer animals than healthy veld of the same size, regardless of what the benchmark says.
• They use long-term average rainfall — not actual current rainfall. In a below-average rainfall year, the benchmark overstates the safe stocking level. Few farmers will ever get exactly the average amount of rain; the benchmark was intended as a useful guideline to facilitate your initial planning. It is not a “law”.
• They do not distinguish between management systems. A farm managed under adaptive multi-paddock/camp grazing in good condition will carry many more animals than a continuously grazed farm of the same size, in degraded condition.

How to Estimate Actual Carrying Capacity for Your Farm

A veld condition assessment will provide you with an estimate of annual forage production at that point in time.

Step 1: Assess your veld condition

Walk or measure representative transects across your different veld types. Record the proportion of palatable grass species vs. unpalatable, make a note of ground cover at root crown level. Take fixed point photographs to show the changes in the veld over a period of years. If you wish you can cut, dry and weigh all the vegetation from a measured area to give you an idea of how much dry matter is there at that time of year. Compare results over the years.

Step 2: Estimate animal grazing requirement

Measure off an area of the veld that you believe a healthy animal would require for grazing for one day. Convert that to an estimate of the area required by your herd per day, at that time of year, given that the animals would not eat everything. You will know of what the veld looks like where they are grazing at the moment, once they leave a camp, to guide you in your estimation of how much they do eat. This method can be particularly useful during the dry season, to plan for how much reserve will be required to take your herd through to the next wet season.

Step 3: Calculate the per-LSU annual requirement

A herbivore will typically consume between 2% and 4% of its body weight, live mass, in dry matter every day. We can estimate that one LSU needs 3% of its body weight per day. A 450 kg beast therefore requires up to 13.5 kg dry matter per day — approximately 4,900 kg per year.

These estimations may prove helpful if you have an accurate assessment of how much dry matter is available at the time. By far the best way to keep track of dry matter production in the veld is by way of grazing records that record the number of animal units (LSU) on the farm every day linked to a periodic assessment of veld condition and records of actual rainfall. Analysis of these records will display production patterns from year to year and calculate grazing capacity as a function of actual rainfall. 

How Regenerative Grazing Changes the Equation

Here is the critical insight: your carrying capacity is not fixed. It changes — upward or downward — based on how you manage the land.

A farm transitioning from continuous grazing to well-planned rotational or adaptive multi-paddock/camp grazing typically sees effective carrying capacity increase over 3–5 years as veld condition improves. Root systems deepen. Soil biology recovers. Species composition shifts back toward palatable grasses. Water infiltration improves. More of the rainfall becomes productive forage.

The farms I have worked with that have fully transitioned to adaptive multi-paddock/camp grazing have consistently achieved significantly higher carrying capacity within five years — not by ignoring the land’s limits, but by improving the land’s capacity to produce. My expectation is that the grazing capacity (i.e., consumption by farm livestock) will double per unit of rainfall in five years.   

Carrying Capacity vs. Actual Stocking Rate

Your stocking rate is what you actually carry. Your carrying capacity is what the land can support sustainably. The gap between the two is your management challenge.

If you are currently stocked above your calculated carrying capacity to the detriment of the land, you have three options: destock, improve the land’s capacity through better management, or a combination of both. There is no fourth option that does not eventually damage the land.

Further Reading

These pages go deeper on the specific topics covered in this guide:

• https://herdscape.co.za/regenerative-grazing-south-africa/
• Stock Density vs Stocking Rate: The Two Numbers Farmers Confuse
• Camp Rest Periods: How Long Is Long Enough?