Tillage System and Date of Planting Effects on Yield of Corn on Soils with Restricted Drainage1

Abstract It has been reported that no‐tillage corn (Zea mays L.) production on poorly‐drained soils results in more uneven stands and slower early growth as compared to conventional tillage methods. A field study was established in 1979 at Princeton, KY, on a Johnsburg silt loam (Aquic Fragiudults) intergrading to a Tilsit silt loam (Typic Fragiudults), to compare corn planting dates under no‐tillage (NT) and conventional tillage (CT) systems. For the NT system, a yield increase trend was observed as planting date progressed from the first planting date (late April) to the second (mid‐May). Grain yields from conventionally tilled treatments decreased with delayed planting dates. No‐tillage corn performed better than CT corn during drier growing seasons, and conventionally tilled corn produced yields equal to or slightly higher (no significant differences) for early planting dates, during years in which wet and cool climatic conditions existed during the early part of the growing season. There appears to be a greater risk associated with early planting dates for NT corn on these soils. From a management viewpoint, corn planting on these cooler soils with slow internal drainage can be delayed due to excessive wetness without substantial yield losses if NT management is used.