I often get calls and/or questions about Broomsedge this time of year. Not because it is already growing, but because it is quite noticeable being an orange-brown, “stick out like a sore thumb” kind of grass amongst contrasting new green growth! Broomsedge (Andropogon virginicus) is often called poverty grass. If you dared to take a bite of it, you might understand why livestock don’t like to eat it, especially when it is mature. It is just poor quality. At best, it is about half the quality of desired forages. Paraphrasing William Albrecht (who linked soil health to human health) the plant doesn’t have enough value for a cow to trouble herself eating it. That is a pretty true statement with a couple exceptions. Cattle will sometimes consume a little of that mature Broomsedge along with very high protein watery forage in the early spring to help balance out their rumen. We can overcome this issue with other means. They will also consume it fairly well prior to early boot (seed stem elongation), but it is still far from being choice feed.
Broomsedge generally gets the upper hand in the pasture because of very low phosphorus or available phosphorus levels. It also tends to be worse on thinner, more eroded soils and for a good reason. Low pH combined with low calcium is a better environment for this warm season perennial than any of our cool-season forages and thin eroded soils that are usually more acidic. Low pH aggravates the phosphorus issue even more by tying up even more phosphorus. You can quickly guess the best way to combat Broomsedge…fix fertility deficiencies, especially phosphorus and calcium. Fixing fertility is the first place to start to win the battle over this obtrusive species.
If the Broomsedge present is at full mature height and dense, it would be most favorable to mow or clip it down close to keep it from blocking sunlight from the species we want to grow. Assuming we have good species present, mature Broomsedge can block sunlight from reaching the desired forage species and allow it to keep maintaining the upper hand. If you remove it and then fertilize the cool-season desired forages, you shift the advantage to the cool-seasons. With some management, and the help of cooler soils and earlier plant growth, cool-seasons will compete with the Broomsedge to help crowd it out. It is all about competition. When livestock eat one species more frequently than the other, they give the competing species the upper hand. We have to shift this back the other direction.
Once the cool-season forages have successfully captured the majority of the solar energy and have grown back to an adequate grazing height (generally 10-12 inches), the Broomsedge will start trying to grow too, especially with warmer soils which it likes. Grazing the Broomsedge in this early stage, but not removing too much of the desired species, helps put extra stress on the supporting roots of this poor grass and gives more advantage to the desired species. You won’t remove it all at once, but you are heading in the right direction. Manure can also be very useful in reducing its foot hold as a means of adding some needed fertility.
Increasing fertility can come in different forms. Feeding hay a portion of the winter in these problem areas can add fertility to the site and increase organic matter – this can be a good fix. Hay would ideally be put in place ahead of use and then best utilized under dry or frozen conditions. Only one bale feeding per spot is best. Too much leftover forage will add additional organic matter and nutrients, but will also slow recovery of the desired forage species. It is surprising how quickly some of those areas can heal.
The picture to the right was taken on a small cattle operation. The producer was allocating out forages in small blocks. This site had a fairly dense stand of Broomsedge present with Tall Fescue and a little clover. He did a great job in maintaining cover and grazing the Broomsedge in the whole area except one last block which did not get grazed the last time around. Notice the difference that one timely missed grazing made.
It is amazing what a difference good cover and fertility makes when it comes to weed control. Most weeds are opportunists, just waiting for the right condition and situation.