Farm Horizons, May 2010
Soil compaction yield thief
By Dave Schwartz
Field conditions last fall in Wright County and neighboring county area were less than optimal for fall tillage.
In fact, October 2009 will go down as one of the worst Octobers on record for weather conditions conducive for harvest and fall tillage.
Due to the cool growing season, harvest was delayed several days. Just as soybean harvest began, the weather turned cold and rainy, and basically shut down harvest and tillage for the month of October.
As soon as the rains stopped, crop producers began harvest, even though fields were saturated. Growers, knowing freeze-up could come any day, mudded the crop out and often tilled in mud, too.
I recall one day in particular, when I observed a farmer chisel plowing soybean ground 24 hours after a rainstorm had saturated the soil. It made me wonder. That grower evidently believed “a bad job of fall tillage is better than no tillage at all.”
This was the situation most growers in the entire state were facing. As it turned out, November weather was unusually mild, allowing harvest and tillage to proceed late into the month.
Fields that were torn up last fall will need extra care this growing season. Tillage specialists normally recommend that these fields be lightly tilled in spring to level off ruts.
The goal of spring tillage is to develop a good seedbed that will encourage germination and uniform seedling emergence not break up soil compaction.
Because root development will be hampered by soil compaction, fertilizer placed close to the seed will be beneficial. This will help plants get through stressful periods during the growing season.
The best time to undo soil compaction is with fall tillage. If soils are relatively dry in October, chisel plow at a depth of 10 to 12 inches. This shattering action tends to break up compacted layers of soil, but only if soils are dry.
Researchers recommend tilling no more than 12 inches deep. Tilling 18 to 20 inches was recommended years ago, but that practice requires more fuel and provides no beneficial effects on yield.
Today’s equipment allows growers, if they so choose, to harvest and till through standing water. This, undoubtedly, is creating more soil compaction.
A rule of thumb that I encourage for planting is to wait until fields appear to be ready to plant, then, wait two days and plant. This is a good rule to follow, but more difficult to practice when we know the importance of early planting dates and there is rainy weather in the forecast.