VRT could be used to vary the amount of N applied site-specifically within the field to reflect differing historical yield levels. The result of this Fall band tillage should be greater residue incorporation and faster soil warming than would otherwise occur if the row surface was left under the nearly-complete cover of heavy corn residue until Spring planting on this poorly drained soils. Warmer early Spring soil temperature should enhance early crop growth rate and may result in higher yield potential and faster dry down at maturity. Similarly, row residue management is designed to clear the soil surface in the row region at planting, hasten soil warming and enhance crop growth rate early in the season when soil temperatures are normally cool. This appearance in the top 13 to 18 inches indicates poor drainage critically-high in the root zone.
Poor drainage is a likely restriction on yield in that environment.
The line transect method measures percent surface residue cover. All are inter-related as they influence soil temperature and thereby early season crop growth. Any factor which results in low soil temperature during germination and establishment can result in slow crop development and a reduction in crop yield potential. Heightened drought stress. Surface crusting indicates shallow compaction resulting from heavy rainfall.