My father owns land next to an antique farm implement event site in Dalton, Minnesota. In the fall of 2015, event participants tilled part of a field with moldboard plows. The remainder of the field was chisel plowed. The following year, corn yielded in the chisel plowing 190 bushels per acre versus 215 bushels per acre in the moldboard plowed area.

    My father owns land next to an antique farm implement event site in Dalton, Minnesota.  In the fall of 2015, event participants tilled part of a field with moldboard plows.  The remainder of the field was chisel plowed.  The following year, corn yielded in the chisel plowing 190 bushels per acre versus 215 bushels per acre in the moldboard plowed area.

    This result relates directly to studies by soil scientist Kui Liu relating to phospate stratification in topsoil.  Phosphates are created by decaying plant matter and are critical fertilizers.  

    Chisel plowing leaves a considerable amount of plant matter at the field surface.  In northern climates, phosphates created by these decaying plants are dissolved and carried off the field during snowmelt while the ground is frozen.  Moldboard plowing turns the surface soil over, retaining surface phosphates into the next growing season.

    "In a field experiment conducted in southern Manitoba, researchers found that phosphorus loss is reduced by 42 percent when the conservation tillage cycle is broken and the field is tilled every second year." - Robert Arnason

    http://www.producer.com/2013/08/study-results-encourage-tilling/