Reducing or eliminating chemical inputs for pasture weed control

Pete Bauman
SDSU Extension Range Field Specialist

As an Extension specialist for South Dakota State University, I’m passionate about our grasslands, and I’m a staunch advocate for keeping our grasslands intact, especially when it comes to converting native pastures to cropland. We’ve seen plenty of grass conversion in both high and low grain markets, so I shouldn’t be surprised when I see grass go under, but it still often catches me off-guard. With the present economic and climate situation — low prices and high water — why we still have land going under the plow is somewhat of a mystery, but I think it centers on not understanding the true value of diversity on the landscape.

However, the plow isn’t the only threat to grasslands today. The second, perhaps more complex issue is to curb our dependence on chemicals for rangeland management. The problem is overuse coupled with a general lack of understanding of how, when, where, and why to and an unrealistic sense of what we believe they will accomplish. More or less, most pasture chemical management is like using a hammer when you really need a scalpel. Its cliché, but true. This ‘browning’ of the prairie is often coupled with poor grazing management, and thus our native diversity of flowering plants and lush native grasses slowly gives way to a pastures dominated non-native grasses that are largely devoid of native flowering plants — plants which have a place and which livestock will use and benefit from when given the chance.

The South Dakota Grassland Coalition and partners have begun work on an educational program that will highlight the pitfalls associated with ‘chemical first’ pasture management. A major theme of this project is to not only identify the downside of broadcast chemical miss-management, but to offer tangible advice on identifying root problems and real-world, workable solutions.

Those solutions are highlighted, in part, on the Rock Hills Ranch near Lowry, S.D., where father and son team Lyle and Luke Perman have taken great strides to understand the underlying drivers that make their ranch successful, including plant diversity and ecology. Ultimately, success hinges on understanding the carrying capacity of their ranch. From this knowledge, opportunity abounds, because not all species of plants are factored into the carrying capacity for cattle. Further, weeds of real concern like leafy spurge or wormwood sage are not generally palatable to cattle, while others are native plants that might be out of balance or underutilized like buckbrush (or goldenrods farther east).

There is a misconception that persists in modern ranch management that has convinced cattle producers that by investing in chemical inputs they will reduce weed competition, therefore grow more forage and increase carrying capacity; increasing total production and thus more profit. While in theory this sounds reasonable, in reality it largely not proven and has led to landscape level economic and ecological costs that are astounding.

You may disagree, but let’s first take an honest look. If our current system was working, we should be ‘winning’ the weed war with chemicals, but, simply put, we are not. What we have in many cases are weedy pastures with reduced carrying capacity due to overstocking, less competition for weeds from our desirable plants, and limited chance for a desirable plant to grow and recover due to season-long exposure to grazing. This gives the undesirable weeds a free chance to grow. And the cycle just continues.

So back to the Permans. What makes them different? Nothing, except a desire to understand more, spend less, increase profits, decrease workload, and improve quality of life. By studying and understanding carrying capacity, they realized that their ranch has a higher capacity for livestock than originally thought because of the plant species cattle do not readily eat. Why spend dollars fighting a futile war with chemicals trying to wipe out those pants on the unproven presumption that the ranch will grow ‘more’ cattle feed? Instead, why not simply take advantage of the carrying capacity that already exists by using livestock that will eat those undesirable plants? Sounds simple. Can it be that easy? Maybe.

Enter the sheep. Not just any sheep. Controlled and targeted sheep grazing specifically designed to take advantage of weedy species without competing with cattle for their preferred plants. This is accomplished through the ancient art of shepherding by man and dog made possible with modern technologies like ATV’s, electricity, plastics, and polyfence.

The Permans are working with a large sheep provider through a ‘package’ deal that includes, man, dogs, and gear, and about 1,000 sheep. Every day the shepherd targets the grazing on forage that is underutilized by cattle. Every night he pens the sheep and the dogs take the night shift, protecting the herd from predators. As for Lyle and Luke, their labor investment consists mostly of directing the shepherd and ensuring he has the resources he needs to get the job done.

At the end of the day, the weeds are controlled, the sheep are healthy, the ranch looks great, the cattle are fed, the shepherd is employed, the Permans spend less and make more and are free to work on other ranch enterprises. It sometimes is surprising how something old can feel new again.

While this system likely won’t work for everyone, it does have great potential to be explored in some form on both small and large pastures. The first step is ensuring an understanding of carrying capacities and stocking rates. The second is finding a sheep producer you can work with. Once the cattle grazing is in order, sheep or goats, may just add enough diversity to the mix to help you turn off the chemical spigot, saving money or making more, and in turn having healthy pastures to pass on to the next generation.

Perman sheep grazing.
Grassland conversion in process, Hamlin County, 2019.