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Discover how managing oak crop trees can improve the yield and quality of forage in woodlands, benefiting both livestock and the environment. Learn effective techniques to open up the canopy and select the best trees for optimal growth and value.
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Forage Yield and Quality Under Oak Crop Tree Management Mike Demchik University of Wisconsin Stevens Point
The Issue • 800,000+ acres of woods are grazed in MN • Foresters ignored the potential for wood from grazed woods • Forage from woods is often low quality and low yield (200 lbs per acre or less) • Most woodlots are overstocked with trees and cattle (too many trees or cattle) • Cattle can damage trees
Cows in an autumn landscape.Viktor Westerholm (1885) Finland
The Question Can management of the woodland benefit the forage yield and quality?
The Effect of Canopy Shading • Cool season and low nutrient plants dominate • Cool season grasses need and can use less light than warm season grasses • Warm season grasses grow MUCH faster than cool season grasses- higher yields • Full canopy can mean less than 100 lbs/acre forage
Side one: How to Improve Forage Growth • Open up the canopy • More light equals more warm season grasses • More light results in more and better forage • Seeding- at low yields may not be economically feasible and what do you plant??
Side two: How to Improve Tree Growth and Value • Open up the canopy • Select your best trees • Remove most of the rest • Use short duration, high intensity rotation during spring or fall (low bugs too) • Avoiding wet soil (swamps) reduces the amount of soil damage
The Idea • Crop tree management is the best solution • Crop tree involves concentrating most of the growth in the stand on the best trees • The inefficiency of crop tree management is that a lot of light makes it to the forest floor • This is where you are growing your forage
The Site • Cass Co., MN, USA • Glossaquic Eutroboralfs soil • Perched water table Oct-June (1 meter of surface), high levels of soil bases, northern mixed sandy-loam Alfisol • Natural forest vegetation (25 m2/ha) • Quercus macrocarpa, Pinus resinosa, Betula papyrifera • Grazed for more than 30 years (possibly 100)
The Project • Three sites marked for crop tree management • Three sites as controls • Cutting done in winter of 2002-2003 • Three fenced sub-plots in each plot (total of 18) • Forage samples taken in early summer and late fall 2003
The Crop Tree System • Release the crown on three or four sides • Target basal area 18.5 m2/ha • Selecting 50-70 trees/ha as crop trees • Leave about 15 feet between crowns of crop trees
Relative Feed Value • In general, early season feed values and protein were similar and good (suitable for dairy animals) • Later season values are poorer overall and worse in the unmanaged stands
Conclusions • Crop tree management has been shown in other studies to be a good method for increasing sawlog value in a relatively short time (10-20 years) • It appears that this method also increases forage production
Will this Work for Farmers? • YES! Minnesota has a very long, cold winter • Farmers often burn wood to heat (up to 10 cords/year of mixed hardwood) • Thinnings from 1-3 acres of crop tree can supply a winter’s firewood • Most farmers are used to “weeding” a garden and “weeding” their woods appeals to them
Past Extension Efforts • Forest management for Cow-Calf operators • Growler series (three sessions included this topic) • A technical publication
Integrating farming and forestry can be ecologically and economically rewarding as well as result in a beautiful landscape.