Final soil manipulation before seed germination occurs during the planting operation. Contact force of depth-gauge wheels adjacent to the seed opener potentially alters the environment for corn seed germination and early plant growth. A field experiment was conducted measuring seed spacing, spacing variability, seed depth, emergence rate, plant dry matter, final stand, crop growth stage, and extended leaf height with different soil contact loads [light, 180 to 490 N (40 to 110 lb); medium, 490 to 890 N (110 to 200 lb); and heavy, over 890 N (200 lb)] and a range of three soil moistures (dry, moist, wet). A treatment with randomly variable contact load similar to that of a conventional planter (control) was also included.
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