By the time soils dry out for fieldwork, the calendar will be clicking near the date when many people like to start planting. The dilemma this spring could become, especially fro those who didn't do a lot of field work last fall, do you till this spring, or move into planting mode?
Agronomists typically warn to be cautious about deep spring tillage, such as moldboard or chisel plowing, especially if it's done while soils are wet. Long-term data dating back to the days of Purdue University agronomist Don Griffith, now retired, and Jerry Mannering, his cohort, usually showed a disadvantage for deep spring tillage eon most soils.
However, options may be limited. Gary Steinhardt, another Purdue agronomist and soils specialist, says the disk is great for building roadways, but not so good for tilling land, especially if soil is in the 'it's just a little heavy but I'll work it anyway stage.' That's when some of the worst soil compaction can occur, he notes. And he also notes that up to 80% of all soil compaction created in a single year can occur on the first pass with the tractor and implement across the field.
Yet no-till corn after corn has also not proven successful in many tests conducted across the state through the years by Purdue agronomists. Anecdotal evidence from farmers typically claims better results for no-till corn after corn than what agronomists report, but the results seem to vary greatly year-to-year. No-till corn took a big hit in the very dry early spring season of 1988, certainly a stressful year for raising corn in Indiana.
Whether soil compaction created early causes much problems with yields will depend on the weather that follows during the season, Steinhardt says. If rainfall is plentiful and crops are not stressed by other factors, then soil compaction may cause minimal yield loss. However, it's another stress that can add to the load if the crop becomes stressed by dry, hot weather. Soybeans typically show less impact from soil compaction in any one season than corn, no matter what the conditions.
If the field is unlevel or was rutted last fall during harvest, then there may not be much option but to do some form of tillage, experts notes. One choice is to till in the ruts, or till the entire field very lightly. Some of the newer tillage tools, especially the newest release from Case IH, is actually designed to till as shallow as 1-inch deep and still provide leveling action. In test runs made exclusively for Indiana Prairie Farmer last fall, this tillage tool left a large amount of residue on the surface, tilled only an inch deep and yet left the field level enough for planting. It can also run deeper if the operator thinks it's necessary.
The bottom line will obviously be to analyze tillage option and planting methods carefully this spring. More wet weather extending into April, if it occurs, may only complicate the siutaiton.