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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
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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.