Green is Good, Brown is Bad: Evaluating Pastures in the Fall

For producers  with cool season grass pastures, fall (especially after frost) is an excellent time to quickly evaluate the health and productivity of pastures. If green grasses dominate the pasture, it’s likely that most of those are cool season grasses and they are growing with ideal temperatures and rainfall and good soil fertility. Brown pastures at this time are either dominated by warm season grasses, or they are cool season grasses starved of soil fertility or drought stressed. While managers can’t make up for warm temperatures or poor rainfall, we can take steps to determine if pastures are deficient in soil nutrients or overrun by warm season grasses. Your local county extension agent or farm consultant can assist in identifying cool season and warm season grasses, as well as collecting soil samples.

For those who want a more objective measurement of cover, there’s a phone app! Developed at Oklahoma States University, Canopeo is a multipurpose green canopy cover measurement tool. Canopeo allows users to photograph a pasture close up and analyze the photograph for green and brown pixels. Green pixels show as white and are healthy, living material and likely productive, although green weeds will also be counted. Brown pixels are shown as black and represent bare soil, dead or dying material, dormant plants or a closely grazed pasture.  According to the developers, pictures should contain more than 60% green material to graze. Pastures with less should be monitored closely and those with much less green (<40%) should not be grazed. While this app cannot replace a visual inspection by managers, it does provide a more objective measure of pasture health. Canopeo is a free app, available on both iTunes and Google Play.

Late fall (after frost) is a great time to visually evaluate the health and productivity of your cool season grass pastures. With cool season grasses (and legumes) active and warm season grasses dying or going dormant, color is a simple way to observe the overall composition of your pasture. Remember the phrase originally coined by Dr. A.J. Powell, Jr., (former Turf Specialist at the University of Kentucky), “Green is Good, Brown is Bad.” ~ Krista Lea and Tom Keene

Photo:(Left) Cool season grasses and legumes are still active and green in early November. (Right) Canopeo detects nearly 99% green cover in the picture (green is shown as white).