Subsoiling can help improve yield potential of certain poorly drained soils, a six-year study by ag engineering researchers at Ohio State University (OSU) shows.

Corn and soybeans grown on subsoiled plots yielded about 5 percent more than crops grown on nonsubsoiled ground during a study begun in 1991 at the Ohio Agricultural Research and Development Center in northwest Ohio.

According to OSU ag engineer Randall Reeder, long-term data showed corn yielded 110 bushels per acre or about 5 bushels per acre more than non-subsoiled plots. Soybeans yielded 35 bushels per acre or almost 2 bushels per acre more than nonsubsoiled plots.

Using typical corn and soybean prices, the yield increases would return about $2 for every dollar spent subsoiling, he says.

“There are a lot of subsoilers used in northwestern Ohio,” Reeder says. “If it didn’t pay, there wouldn’t be that much subsoiling going on.”

Cart Compaction

Researchers used 10- and 20-ton grain carts to compact every square inch of soil three years in a row on plots at study sites.

After the compaction, yields drastically declined compared to non-compacted plots. The 10-ton plots recovered naturally by 1992, but the 20-ton plots did not return to normal yields until 1997.

Starting in 1991, Reeder subsoiled some compacted and non- compacted plots every two years. Subsoiling helped repair the compaction damage and helped yields on non-compacted plots.

The 1997 data showed corn and soybean yields on subsoiled plots were 5 percent and 2 percent higher, respectively, than on non-subsoiled plots. Soybean…