This field in Christian County, Kentucky, is apparently enrolled in the Crop Reduction Program (CRP.) The land hasn't been touched for several years. No crops have been raised. There's been none of the usual plowing, cultivating and harvesting. It hasn't even been mowed.
Look how the young redcedars (juniperus virginiana) are coming into the abandoned field. The redcedar is a pioneer species, and old fields are one of the places where it frequently invades and establishes itself. Hardwoods may eventually follow, but first redcedars will have their day.
I took this photo this morning, and you can see that the cedars are still in their reddish-brown winter color. In summer, they will become much greener.
The berry of the redcedar is eaten by many birds and animals and the seed is distributed as it passes through their digestive tracts. This is apparently how the seeds have spread across this field. It also accounts for the many, many redcedars that grow in fencerows here: they are the result of birds perching on the fences.
It is interesting that the red-cedar's berry is not really a berry at all, but rather a small, plump, sealed cone. Each cone has up to four seeds in it.
When I was a kid, growing up in the Nebraska Sandhills, the eastern redcedar was widely planted in windbreaks. I suppose it was inevitable that eventually the tree would go wild as birds and animals spread the seeds. When I revisited the Nebraska Sandhills in 2000 for the first time in 15 years, I was shocked to see little cedar trees scattered across many pastures, much like the field in the photo above! Nowadays, ranchers are fighting the tree, instead of planting it. It's ironic.
A similar situation exists in the Missouri Ozarks:
Early surveyors found very little cedar—only on bluffs where fires could not reach it. Nowadays it is everywhere, especially in old fields and disturbed soils. Missouri Department of Conservation and U.S. Forest Service biologists are trying to get rid of the cedars that have invaded old fields, to restore the cedar-free savanna and prairie-like habitats that once characterized the flatter uplands of the Ozarks.
Source: "Native plant of the month: Red Cedar" by Dr. Lynda Richards, published in The Ozark Chronicles
The field in the photo above will soon become a field of red-cedars if nature is allowed to take its course. The field is not beyond reclaiming yet. It could still be brush-hogged. Most areas could be plowed without too much trouble from tree roots. But if the cedars are allowed to continue growing here, this soon won't be cropland anymore.
My personal opinion: I hate to see this field being taken over by redcedars when we are looking at corn shortages due to the demand for corn for ethanol. It is time to eliminate some of the crop reduction programs and bring fields like this one back into production.
A few champion Eastern redcedar trees
Eastern redcedar: A tree that birds love
Large Eastern red cedar tree at Fort Donelson, TN