Editor's Note: The is the summary of the article, which appeared in the American Society of Agronomy's Agronomy Journal in 2004. You can view a pdf of the entire study here.
Field studies were conducted in Illinois in 2000 and 2001 to determine if differences exist in weed emergence patterns, weed control, corn plant population and grain yield in strip-tillage, conventional tillage and no-tillage production. Weed emergence peaked at 2 and 4 weeks after planting (WAP) in 2000 and 2001, respectively.
Weed emergence at 2 weeks after planting in 2000 was greater in conventional tillage compared with no-tillage and strip-tillage. Tillage system did not affect total weed species emergence in 2001.
In both years, lower control of giant foxtail and common waterhemp occurred following acetochlor plus atrazine applied pre-emergence in no-tillage compared with conventional tillage. Control of common waterhemp in 2001 and giant foxtail in both years was similar with glyphosate applied post-emergence, regardless of tillage system.
Corn population was greater in conventional tillage compared with no-tillage in 2000 and greater than the population in no-tillage and strip-tillage in 2001. But when averaged across weed management strategies, corn yield was greatest in strip-tillage in 2000 and conventional tillage in 2001.
No-tillage corn production systems have not been readily adopted in Illinois in spite of the environmental benefits. In fact, no-tillage corn acres declined from 19% in 1994 to 14% in 1999, according to the Illinois Department of Agriculture.
No-tillage corn yields have not been as satisfactory as conventional-tillage corn possibly due to lower soil temperatures early in the growing season reducing seedling emergence and early growth. Reduced soil temperatures are directly related to the amount of surface residue in a no-tillage system.
Higher soil moisture and lower soil temperature in a no-tillage system compared with conventional tillage can also delay corn planting.
Strip tillage may provide corn growers with an attractive compromise between no-tillage and conventional tillage production systems. Strip-tillage creates a narrow zone for planting in which soil temperatures in the planting zone are increased and soil drainage and aeration are improved.
The favorable conditions in this zone may allow for timely planting and more even crop emergence compared with no-tillage. The mulch layer maintained in the strip adjacent to the zone for planting provides protection against soil and wind erosion and conserves moisture similar to a no-tillage environment.