How to Estimate Vegetative Cover


Properly managed pastures are a great source
of nutrition for grazing animals. A dense stand of vegetation in pastures also helps
reduce soil and nutrient losses into nearby water sources.
Bare or open spots in pastures are unproductive and allow for weed encroachment and soil erosion.
Therefore, farm operators should also strive to maintain a pasture vegetative cover of
at least 70%. Put simply, pasture vegetative cover is an
estimate of the percentage of grasses, legumes like white and red clover, and weeds in a
pasture compared to bare soil. Knowing the percent vegetative cover in each
pasture will help you determine whether a pasture requires additional management practices
or if it needs to be renovated. This video will teach farm operators how to
estimate pasture vegetative cover using the simple and practical step-point method.
In the Mid-Atlantic region, the best time to estimate pasture vegetative cover is in
mid-summer during July or in late fall during early November.
To get started, first mow or graze the pasture to a height of 3 to 4 inches.
Next, make a small white mark on the tip or side edge of a shoe or boot with white paint
or whiteout. Print or prepare a form to record your results.
Your form should include a table with 50 rows and 5 columns, with the columns labeled grass,
legume, weed, soil, and other. Make sure to bring along a pencil or pen.
A clipboard can also come in handy. Walk through the pasture in a random zig-zag
pattern stretching from one corner of the pasture to the other. Avoid walking through
heavily trampled areas like near gates, waterers, laneways and feeders.
Every 5 to 10 steps, stop walking. For smaller or larger pastures, you may need to adjust
the number of steps you take between stops in order to cover the entire pasture.
At each stop, look at what is underneath of the white mark on your shoe. It will fall
directly on top of a grass, legume, weed or bare soil.
On your results form, mark an “X” in the box corresponding to the step number and the type
of pasture cover under the white mark. If the white mark falls on top of something
other than plant or bare soil (e.g. rock, trash, or hay), mark the box labeled “other”.
After recording 50 stops, add up the number of X’s for each pasture cover type and record
that in a totals box at the bottom of the page.
Calculate the percentage of pasture vegetative cover for each cover type by multiplying the
number of X’s in each column by 2. For example, if the white mark lands on top of a grass
species 23 times out of a total of 50 stops, the percentage of grass in that pasture is
23 x 2=46 or 46 percent. If your pasture contains more than 70% vegetative
cover, you’re doing a great job! You can continue to maintain your current level of pasture
management practices. If your pasture contains 50-70% vegetative
cover, renovate the pasture through weed control and reseeding, and improve pasture management
practices like soil testing, mowing, and fertilization. If your pasture contains less than 50% vegetative
cover, you should consider killing off the existing forage with an herbicide and reestablishing
the pasture with desirable grass or legume species.
You are now all set to estimate pasture vegetative cover on your farm using one of the easiest
methods available. Good luck! This video was brought to you by University
of Maryland Extension, providing solutions in your community.
To learn more about our programs, or to locate an office in your county, visit extension.umd.edu.