Grazing for Interseeding

Pastures and hay meadows provide higher quality feed, are more productive, and require fewer inputs when they have good forage legumes growing in them.

Outside of moisture, nitrogen (N) is often the limiting nutrient in pasture production.  This is especially true for cool season pastures that are primarily dominated by introduced grass species.  While our native grass pastures developed in a N scarce environment and don’t require nitrogen fertilization, introduced grasses like brome, orchardgrass, fescue, and timothy will benefit.  Commercial fertilizer may be a quick and easy option when looking at pasture fertility, but it’s costly.  Instead, maybe we can grow our own N using legumes.

Do you have a pasture area or hay meadow that is relatively free of weeds?  If so, take a small portion, no more than about 15 percent of your total pasture acres, and graze it down.   From now until that grass will grow no more this year, I want you to graze that grass hard.  Grub it down, then graze it some more. Maybe you’ve already accomplished this with the dry conditions this summer. 

Now why would I recommend overgrazing?  Surely it will hurt the grass. First, because we will be stressing the grass, we want to follow the 15% rule closely so we don’t put our entire forage resource into deficit next spring.  Still, setting the grass back is exactly what we want.  Next spring, you will interseed legumes like red clover, white clover, birdsfoot trefoil and alfalfa into that grass to make it more nutritious and productive.  We may even consider a winter frost seeding if conditions are right later on.

The biggest challenge to establishing legumes into a grass sod is competition by that existing grass on new, slow growing legume seedlings.  Anything you do to reduce competition and slow down grass growth will help.  Overgrazing this fall prior to next spring’s seeding will weaken the grass and slow its spring growth, thus giving new legume seedlings a better chance to get started.

And while we’re doing what we can for the legumes, let’s take some soil samples too.  Legumes are especially sensitive to soil pH and can benefit from proper phosphorus levels to really get up and going.  When we get our analysis back, we can see if adjustments are required and apply any needed fertilizer.  A pH of at least 6.5 is recommended for clovers and birdsfoot trefoil.  Alfalfa is a bit pickier, with a recommended pH of 6.8-7.0.

After interseeding next year, we want to keep an eye on the new seedlings and manage grazing accordingly.  Avoid closely grazing the pasture where the new legumes are growing, but we still want to limit surrounding vegetative growth and competition.  This is a tricky balance to achieve.  Quick rotations or flash grazing may be one of our best options grazing wise.  We always have the option of bringing out the mower and adjusting the cutting height to right above our new seedlings if all else fails.

So, consider adding some legumes to your pasture next spring.  Graze your grass this fall until virtually nothing is left.  Then, keep grazing a couple weeks more just to make sure. Legumes you add next spring will establish better because of it.

-Ben Beckman is a beef systems Extension Educator serving the counties of Antelope, Cedar, Knox, Madison and Pierce.  He is based out of the Cedar County Extension office in Hartington.  You can reach him by phone: (402) 254-6821 or email: