There's an old saying that "You can't make a silk purse from a sow's ear." In other words, if you start with something ugly you can't make it into something beautiful. This also applies to attempts to convert wooded tracts and other non-cropland areas into productive cropland and pastures - with some exceptions.
"Two rocks for every dirt"
I have some experience on this subject, because during the 1980s when I was managing Miner Institute's field crop program, we converted 120 acres of unused land into cropland. Of this, one-third had previously been permanent pasture while the rest was wasteland, including some fields where we had to grub out trees that were up to a foot in diameter. Most of the pastureland was so stony that I often refer to it as having "two rocks for every dirt," and that's an understatement! I have nothing against pasture, but this land was too far from the livestock barns to be practical for pasturing cows or heifers. We tried sinking a plow into one of these pastures and quickly realized that wasn't going to work, since plowing and then picking stones would have resulted in lowering the elevation of the entire field. So, taking one pasture at a time, we applied glyphosate to kill the old sod and then planted no-till corn. This wouldn't have been possible before the advent of effective herbicides and no-till corn planters, but after a couple of sensational failures, including our first attempt at no-till corn when we planted it twice and wound up with less than half the desired population, we got good corn yields. Not quite as good as our "regular" cropland, because this land is drought-prone, but more than enough to justify the time and expense. When we started seeding alfalfa grass on this land, also using no-till or minimum till, yields were close to that on our conventionally tilled cropland. That's because alfalfa is a deep-rooted crop, better able to withstand dry spells. Overall, the conversion of these former pastures to rotated cropland was a solid success.
Our success at converting wasteland and brush-covered tracts into cropland was much more variable, ranging from very good to just plain lousy. Two fields, 14 and 20 acres, had silty clay loam soils and were very poorly drained. They had been cropped 50 years ago, but had grown up to swamp grasses and sparse brush. However, there were adequate drainage outlets to these fields, so we first upgraded the old drainage ditches, and then tile drained the fields in a pattern system, with tile lines spaced 50 feet apart. This was successful, and it is now some of our more productive cropland because the only serious impediment to yield was poor drainage.
Finally, there were several tracts of land that had previously been cropped by William Miner that, left alone for at least 50 years, had become overgrown with brush and trees. This land was adjacent to some of our other cropland, so after having an environmental assessment to make sure that we wouldn't be destroying any "rare and endangered" species, we went at it with bulldozer, backhoe and Timberjack, ripping out trees and brush. It was a big undertaking, one we wouldn't have attempted if we didn't have our own equipment and experienced operators. The soils were poorly drained, so we could only do this in midsummer after the soil had dried. We got the land cleared and planted corn, since it seemed the best crop to contend with the remaining tree roots and other plant debris. Corn silage yields were poor, so we only planted corn on this land for one year before seeding it to a forage mixture. That was almost 30 years ago, and the "forage mixture" is now almost 100 percent grass. Unlike the previously mentioned land that we tile drained, there weren't adequate outlets to these fields. Because of frequent delayed harvest due to wet conditions, both yield and quality have been modest at best. Now we know why these fields had been left fallow for half a century.
Listening to Cato
Marcus Cato was a Roman author who died over 100 years before the Christian era; one of his writings concerned the purchasing of farmland. A Cato quote worth remembering: "Beware that you do not rashly condemn the experience of others." If you're considering bringing land into production that has never been farmed, or was once farmed but has since been abandoned, ask yourself: Why isn't this land in production? Is it wet? Stony? Subject to flooding? A first step is to take a soil sample, and when reviewing the analysis pay particular attention not only to soil pH, but also to the lime requirement. Some years ago, a farmer was considering buying a large tract of land, but before doing so he asked my opinion. I looked at what was (and wasn't) growing there, and recommended that he get a complete soil analysis before making an offer. When the soil test results came back, we discovered that it would require over 20 tons of ag lime per acre to increase the soil pH to 6.2. It would have cost more to lime that land than the total asking price. (He didn't buy the land.)
Making land conversion decisions on your farm
Should you try to convert non-cropland to rotated cropland or pasture? If the land in question hasn't been in your family for a long time (or ever), ask some old-timers in the area if they know why the land is in its current unused state: Remember Cato's comment. Try to determine the impediments to crop production, starting with a soil test and then consulting someone from your local soil and water conservation district for an evaluation of the soil types. Acid + wet + stony is often a fatal combination, making renovation not worth the time and expense. A soil analysis should precede any renovation attempts: Note that some forest soils are extremely acidic. If you rip out brush or small trees, count on the fact that you won't get nearly all of the root systems, so a clean-tilled crop such as corn for at least a couple of years would be advisable to give the roots time to rot. Also, corn will better tolerate moderately acid soil as you apply any necessary ag lime to raise the pH. Finally, don't let any land renovation stand in the way of timely planting and harvest on the land you're currently cropping.
Ev Thomas has worked as an agronomist in New York for 45 years, first with Cornell University Cooperative Extension, then with the William H. Miner Agricultural Research Institute in Chazy, N.Y., including managing its 680-acre crop operation. He continues to work part-time for Miner Institute and is now an agronomist at Oak Point Agronomics. He has a written our Forage column for over 13 years and has been an expert contributor on a number of other topics. Comment or question? Visit www.farmingforumsite.com and join in the discussions.