Results from Subsoiling and Deep Fertilization of Corn for 2 Years

Abstract

AbstractData on six soil types in North and West Florida for 2 years were used to evaluate subsoiling and deep placement of fertilizer. Lime, fertilizer, fertilizer plus lime, and fertilizer plus lime plus minor elements placed in the subsoil were compared with subsoiling alone and surface fertilization at low and high rates. Corn yields, root distribution and the chemical composition of ear leaves were used to measure responses.Where organic hardpans existed, as on the Leon fine sand, Ona fine sand, and combinations of these soil types with related soils, yield increases were obtained for subsoiling alone and fertilizer, lime and/or minor elements placed in the subsoil. Responses to fertilizer were related to the chemical composition of the soil profile and rainfall distribution. Better responses were obtained when moisture stress periods occurred during the first part of the season. The Norfolk loamy fine sand, Ruston fine sandy loam and Red Bay fine sandy loam soils contained compact clay zones or plow soles beneath the surface. When drought periods were of short duration, subsoiling and deep placed fertilizer improved corn yields above the check. When the drought period was of 25 days' duration the advantage of having a deeper root system and a larger corn plant was lost.On the Klej fine sand where there was nothing in the profile to impede roots, fertilizer on the surface was as good as. deep placement and subsoiling alone was of no benefit.The residual effects of the subsoiling treatments were generally small. There was some indication that it would be necessary to subsoil annually even though additional fertilizer in the subsoil may not be needed.