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PERENNIALS

Forbs: The Forgotten Third Component of Pastures nematodes. It has very deep taproots and seems impervi-

In the 1950’s, the introduction of the herbicide 2,4-D ush- ous to soil compaction. Livestock find it very palatable and
the foliage is highly digestible and high in protein (30% or
ered in a new era of pasture management, in which pro- higher), until the plant bolts (forms a flowering stem) when
ducers were able to selectively eliminate “weeds” in pastures it becomes far less desirable. It is one of the highest yielding
and create nearly pure stands of grass. We soon found out pasture species available, comparable to alfalfa in yield if
that a pure grass stand was not as productive as a pasture there is sufficient fertility.
with mixed, diverse vegetation. We first attempted to im-
prove productivity with nitrogen fertilizer, which helped, Plantain is a perennial low-growing forb that may be even
but found that animal performance was not as good as on more winter hardy and indifferent to compaction than chic-
a mixed pasture. Interseeding legumes can improve pasture ory. It is rapidly gaining popularity, and the people who use
nutrition, but the more productive legumes like alfalfa also it love what it does for both soil and livestock. It is very
carried a bloat risk. However, for more than a century there palatable and nutritious, has a high mineral content, and re-
has been a small group of pasture enthusiasts who have been grows rapidly after grazing. It contains strong antimicrobial
advocating the inclusion in pasture seedings of a little used compounds which help animals fight off infectious diseas-
class of pasture plants: forbs, or herbs as others call them. es, and functions in the rumen similar to ionophores like
rumensin and bovatec, increasing animal feed efficiency.
Ecologists regard weeds as a sign that there is an unfilled
niche; in other words, they are an indicator that there is
sunlight, moisture, or soil resources that are not being ex-
ploited by what we have planted. The only difference be-
tween a weed and a forb is that if livestock eat it, we call it
a forb, and if they don’t we call it a weed. If weeds thrive
in a pasture situation it is a good sign that some forb will
also be successful, as long as proper grazing management is
applied. Selected forbs are much higher in mineral content
than either grasses or legumes, and many contain chemi-
cal compounds that boost animal performance, including
some that help prevent legume bloat. In addition, if forbs Burnet is one of the most drought tolerant forbs, and is un-
are included in a pasture seeding, they fill the niche that usual among plants in that it retains its nutritive value at all
would otherwise be occupied by weeds, and therefore sup- seasons and growth stages, even in winter. This is a valuable
press weed encroachment. characteristic to livestock, but also to wildlife. There are
stories of deer pawing through deep snow to eat still-green
Some of the more valuable pasture forbs include: burnet plants in midwinter.
Chicory is a perennial forb that has gained quite a foothold These plants are some of the absolute best plants avail-
in pasture circles. Compared to other plants, chicory con- able for breaking compaction. Often the best compaction
tains relatively high levels of minerals such as potassium, remedy involves the seeding of a forb-rich temporary pas-
calcium, magnesium, sulfur, zinc, and sodium, which are ture, inoculating the seed with mycorrhizal fungi, and graz-
necessary for animal health. Chicory also contains com- ing it for a year or two. The action of the forb roots, the
pounds that reduce bloat and reduce intestinal parasitic grass roots, the mycorrhizal hyphae, and animals such as
dung beetles and earthworms act to penetrate and loosen
the tightest, heaviest plowpan.

Including a few forbs in a pasture seeding can make the pas-
ture more productive, more nutritious, and make the ani-
mals grazing it healthier. Forbs can also have a great benefit
upon the soil itself, deepening the root zone and alleviating
compaction.

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