|Iqbal Muhammad, - IOWA STATE UNIVERSITY|
|Marley Stephen J, - IOWA STATE UNIVERSITY|
Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Abstract Only
Publication Acceptance Date: June 23, 1995
Publication Date: N/A
Technical Abstract: Smearing of seed furrow sidewalls, resulting in a thin layer of compacted soil on each side of the V furrow occurs under certain soil texture and moisture conditions. This smeared layer can make the sidewall nearly impervious to root penetration, resulting in poor stands and poor root and plant development. Replicated field trials in a clay loam soil of two coulter treatments (1 coulter and 3 coulters spaced at 7.5 cm) ahead of conventional double disk furrow openers were conducted to evaluate their effects on sidewall smearing and corn germination, emergence, and early plant development. A third treatment was planting with a no leading coulter (0-coulter). Possible smearing effects were evaluated by furrow sidewall air permeability , soil bulk density and cone index measurements. Air permeability for the 3-coulters treatment was greater than for the 1- and 0-coulter treatments. Seed zone bulk density was reduced by planting; the 3-coulters treatment produced a lower bulk density than 1- or 0-coulter. Cone index values both below the seed and in the sidewalls were lowest for the 3-coulters treatment. There were no differences among treatments for total emergence, but the 3-coulters treatment had the lowest emergence rate index (slowest emergence) and the lowest plant dry weight after 42 days. For this field study, the 3-coulters treatment virtually eliminated smearing, but resulted in lower plant dry weight.