Vertical Tillage Effects On Corn Yield, Disease and Pathogens, and Soil Properties.

In the Midwest there has been an increase the number of vertical tillage (VT) implements sold and a large push in marketing these newer implements to producers.  Vertical tillage is defined as shallow tillage, usually in the top 5 to 7.5 cm of the soil and results in no horizontal disturbance of the soil.  The objective was to determine the short-term (one growing season) effects of a vertical-tillage operation on seedling emergence, crop growth and development, yield, residue decomposition, disease incidence and severity, quantification of pathogen propagules in soil and crop residue, and effects on the near-surface soil physical properties.  The study was conducted during the 2010 growing season at four locations throughout Kansas and compared vertical tillage against the producer’s current practice of no-till (NT) or strip tillage (ST).  In NE Kansas, VT was compared to NT and conventional disk.   Bulk density at a depth of 0-5cm under the NT conditions had a value of 0.95 g/cm³, versus 0.78 and 0.80 g/cm³ in the VT and disk treatments respectively.  Under NT the infiltration rate (0.84 mm/hr) was significantly lower (P=.05) than VT (2.12 mm/hr) and conventional disk (1.29 mm/hr).  Disease severity (lesions per plant) was higher in NT (71.8) than in the VT (46.3) and disk (42.8) treatments, which might be attributed to the higher residue cover in the no-till (60.2%), compared to the VT (40.8%) and disk (35.6%) treatments.  Overall, any differences in the soil, plant, and pathogen indicators have not resulted in significant yield improvements at any of the four site locations, but more site years will be needed to assess any potential benefits of VT.   Information gained from this project will be disseminated to extension clientele including extension educators, producers, commodity groups, and agricultural professionals.