How to Estimate Vegetative Cover

Effectively 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. Learn 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 mark on the tip or side edge of a shoe or boot.

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 are doing a great job! You can continue to maintain your current level of pasture management practices and may only need to address weed control issues. 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.