(The following is from my monthly newsletter. This series began in March 2022 and has continued for nearly a year, with its final installment in February 2023. Below is the “better” edited version I initially emailed my followers.)

This time, we switch gears and look at Grazing Tools. The first tool we’ll examine is Time. We use community dynamics to build biology, influence the presence of desirable and undesirable biological organisms, and better understand how ecology functions.

Time in Growth and Yield

Plants take time to grow, like any living thing. They reach a certain point where it’s best to graze them for optimum quality and yield. They also reach a time when it’s “too late” to graze (not really, it’s all in context; sometimes it’s good to leave certain areas to graze later in the year when plants are dormant) because they’ve reached maturity and have set seed. Their roots also take time to grow, allowing them to store energy and divert resources to soil microbes instead of sacrificing themselves to grow leaves.

They grow in an S-curve. In the first phase, the plant switches from taking energy from the roots to grow new leaves to generating energy from the leaves via photosynthesis. The second phase is very quick, as the inflorescence (seed head) is close to emergence. Once the seed head emerges and begins flowering, phase 3 starts, where yield is maximized, but quality declines the more the plant matures.

Time affects quality and yield (as do other factors, including soil fertility and precipitation). This is where the best time to start grazing and when to return to the paddock or pastures that have previously been grazed is determined. The target should be what is considered “optimum, ” typically at phase two (or stage two, above) growth phase. Plants are deemed “ready” at that stage because the top growth shows it’s ready, and the roots are also fully recovered.

Roots are crucial for grazing. They ultimately explain how mismanagement can negatively impact the pasture stand. Roots also need time because, post-grazing, the plant is forced back to early or late square one (or stage/phase one), where energy must be brought up from below ground to start growing new leaves. As a result, a bit of the root material sloughs off.

What sloughs off must be regrown; as above, so below. During this regrowth process, the plant is most vulnerable to being re-grazed because roots are trying to return to what they were before grazing. Should they be grazed when plants aren’t ready, more root material is sloughed off, leaving even less than before. This means plants will either need even more time to recover or end up being stunted and pasture yield compromised. (This isn’t as noticeable immediately; it often takes a few years of repeated overgrazing to see the results.)

Of course, how much is removed is also time-dependent (see graph below). The more that is taken, the longer plants need to recover.

Thus, the less biomass is taken, the shorter the time is needed for plants to recover. When older plants are grazed, taking less than half of the present biomass, less time is usually required for plants to recover (the exception is if they are fully mature).

But that’s the thing: Time is needed for plants to recover. This is absolutely crucial in maintaining the integrity of the stand and its longevity. If plants are not given this adequate recovery period, they slowly die out. This lack of recovery time is called overgrazing.

Defining Overgrazing

I’ve heard multiple definitions of overgrazing, from having too many animals on the land (widely accepted yet wholly wrong) to a concept of time where the plants are not given enough time to recover due to management. The best and most concise definition I’ve found is that overgrazing is simply the grazing of the roots.

Severely grazed plants are set right back to square one. They must divert their energy source to the roots and crowns to grow new leaves. Typically, a plant’s primary energy source is in the leaves, but because those leaves are gone, the energy stored in roots or used to grow new roots must be diverted to grow new leaves.

Once the leaf material has been replenished, the plant can focus on regrowing those lost, dead, sacrificed roots.

Thus, overgrazing is “grazing of the roots” because animals are permitted to come back and eat the plant that is in the process of recovery, sacrificing even more roots than before. The image below shows a study that was done by clipping plants at different times to see what happens to the roots. The results are, unsurprisingly, astounding.

Here are just three ways how you can overgraze your pastures:

1. Stay too long,
2. Return too soon, or
3. Start too soon after dormancy has ended.

I wish there were a nice recipe everyone could follow for how long it is too long for animals to graze and when animals can come back after an area has been left to recover. But there isn’t. As we discussed previously, it all depends on how much your animals ate and trampled in that stand; the less they took, the sooner they can return.

What about Too Much Rest?

Total or partial rest is equally as bad as, if not worse, overgrazing. In arid, brittle-tending environments, too much rest means plants are not provided with the necessary disturbance to remove dead material. Grasses cannot shed leaves like trees, which is where ruminants come in to help.

Suppose nothing is there to help trample, eat, or somehow remove some or most of that leaf material. In that case, it shades out the base of the plant, preventing moisture from seeping down (or escaping), impeding tiller growth, and slowly suffocating the plant to death. The material doesn’t quickly decompose; much of it will oxidate and turn grey, remaining on the rest of the living plant.

Dead material that does slough off with mechanical disturbances like heavy rain or hail washes away, revealing soil and exposing it to erosion. The more plants die, the more leaf material gets washed away, the more soil is exposed, and the more eroded away.

Partial rest is a term that came from Allan Savory to describe land that didn’t receive sufficient disturbance by grazing herbivores. They pick the areas they want to eat, over-utilize, and leave the rest alone (a.k.a., continuous grazing). Total rest is the complete absence of any grazing herbivore for an extended period (i.e., over 5 to 10 years, over 20 years, or longer).

Time plays a big role because the longer these areas and those plants experience rest, the more plants die and the more degradation occurs. Areas that are less brittle-tending (or tending towards non-brittle) have fewer such issues, but plant material can still build up over time, which impedes plant growth despite some decomposition processes happening.

Other Timely Factors for Good Grazing

I didn’t mention seasonal growing periods. Springtime is typically the time of year when plants are growing the fastest and when moves must be timely and quick (but not too quick) to keep up with the growth rate of the spring flush. In other words: Grow fast, graze fast.

In the summer, plants slow down their growth rates compared with the spring flush. Hotter days and less rain in the forecast (usually) slow plant growth. Therefore, grow slow and graze slow—but not too slow!

Another million-dollar question every single grazer seems to have a different answer to (lol): How do you tell when a pasture is ready to graze again?

The answer is, sadly, it depends. It depends on what your goals are and your context. That said, probably the best answer I’ve heard so far is from Greg Judy, who has observed that if all the leaves on the grass plants have those pointed tips (as opposed to blunt tips that are a result of sheering from grazing [or mowing]), the pasture is ready to graze. I might add that it’s time to turn the animals in when the flowering heads are just about to emerge (or starting to emerge).

In the end, it’s still, “it depends.”

Because how long you graze will depend on how long you must rest your pastures or paddocks. The vice versa of this is also true.

Key takeaway: The longer they stay, the more they take, and the more time that area needs to recover.

It’s one thing to graze a pasture severely. Severe grazing, by and large, is not a bad thing. But overgrazing, or grazing of the roots, is quite another and should be avoided as much as possible.

Time is always of the essence in grazing, growing, harvesting sunlight, and moving on.