Beyond Tarweed – Thoughts About Why Things Are Changing in Pastures

In the past few years, John Marble has dealt with Tarweed, a vole invasion, and now a new weed. Is it his management, or something beyond his control? I asked him to share his thoughts with us in this week’s Notes from Kathy. It’s a great addition to this month’s Thinking Grazier.

This year, I’m observing another bit of pestilence: a very significant spike in a terrible grass called Hare barley (also known as Barbed foxtail). This is a terrible annual that spreads by seed, treacherous seed that gets stuck in everything: the cows’ mouth, the dogs’ feet, my socks. Cattle will graze it when it is very immature, but it usually matures so rapidly that catching it is almost impossible. Typically, Hare barley is considered to be a sign of poor grazing management, showing up mostly around corrals or barnyards. As far as I know, there is no cure, and not even any real weapon against this rogue grass.

Perhaps right now someone is reaching for a Bible, looking for those stories about fire and floods and locusts being visited upon folks who weren’t quite paying enough attention. Personally, I reached for an old battered textbook from a class called Ecology. It’s an old favorite of mine, with lots of highlighted passages, margin notes, underlining. I read a few chapters with titles like Population Dynamics, Predator-Prey Relationships, and Succession. Pretty heady stuff. When I was done with that, I called my friend Joe. He’s a very successful farmer and a smart fellow.

“Hey Joe, are you seeing any Hare barley popping up, like, a lot more than usual?”

“Yup. Mostly in drier places. Nasty stuff.”

“What do you think caused that?”

“Well, it’s an annual, kind of an opportunist. The seed must be there in the ground, just waiting for something else to die so it has a place to germinate.”

Why is this happening?

Let’s go back to the study of ecology for a minute. It was a long time ago for me, but some of the lessons are still pretty clear:

• All of the organisms in a community are intimately related to one another. Perhaps not genetically, but physically.

• A change in environmental conditions can have significant impact on a particular species or a group of species, and in extreme cases entire biological systems may collapse.

• If conditions return to normal, succession processes will begin working, and the community will begin moving back toward a more familiar state.

So, if I assume that my management of the plant and animal communities that occupy our grasslands has been stable, there must be some environmental change that has brought about the extreme spikes in unusual plant and animal species.

In case some folks haven’t been paying attention, the weather patterns across America (and the world, actually) have been changing, and changing significantly. My world continues to get hotter and drier, hotter and drier. The results of this change in environmental conditions is a bit hard to predict, but one thing’s for sure: there will be results. There will be change on the ground. Species don’t adapt quickly enough to deal with a rapidly changing environment. As my friend Joe mentioned, something’s probably dying to make room for something else.

The result for my landscape: Tarweed. Voles. Hare barley.

I don’t find this situation all that comforting. But I do take comfort from a bit of observation:

• The Tarweed has abated, nearly disappearing in only a few years.

• The Vole population has been reduced by at least 80 percent this year.

As for Hare barley, well, maybe it will get crowded out by some more desirable species next year.

One thing seems clear: the solution to these “problems” will not be found at the farm store. We will continue to manage our lands for healthy plants and animals, and happy people..

Happy grazing,

John