The Effect of Environmental Factors on High Corn Yields (Light, Planting Pattern, Row Width, Nutrients)
Ottman, Michael Joseph
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Permalink
https://hdl.handle.net/2142/71612
Description
Title
The Effect of Environmental Factors on High Corn Yields (Light, Planting Pattern, Row Width, Nutrients)
Author(s)
Ottman, Michael Joseph
Issue Date
1985
Department of Study
Agronomy
Discipline
Agronomy
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Agriculture, Agronomy
Abstract
Corn production plays an integral part in the U.S. economy and is vital to the welfare of people worldwide. The effect of environmental factors on high corn yields was investigated with field studies using supplemental light, planting patterns, and plant competition.
The supplemental light study was conducted to determine the effect of increasing the light received by the lower two-thirds of the canopy on yield. Fluorescent lamps were erected in the field approximately 1 week before silking and supplemented the light intercepted by the crop up to 55%. Photosynthesis by the lower leaves increased throughout the grain fill period due to increased light. Uptake of N, P, and K was increased 90, 90, and 30%, respectively. Yield of all plant parts was increased up to 50 to 60%. The yield increase was due to increased photosynthesis of the lower leaves benefiting carbon and/or mineral metabolism.
The goal of the planting pattern study was to determine if increasing the amount of light intercepted by the lower leaves by varying planting pattern would increase corn yield. The planting patterns consisted of 38-38, 13-64, 76-76, 13-102, and 13-140 cm between adjacent rows. Wider row spacings increased the amount of light intercepted by the lower leaves. However, corn yield was lowest for the widest row spacing (13-140 cm) due to less total light interception.
Plant competition in outside rows was investigated to determine why outside rows of corn yield more than inside rows. This investigation was separated into three studies. In the first study, competition in outside rows was reduced due to proximity to an unplanted border. Enhanced light interception and nutrient uptake were associated with the yield increase in the outside rows. The relative importance of above- and below-ground competition in limiting corn yield was assessed in the second study. Under our high-yielding environment, above-ground competition was the major yield-limiting factor. The time period when competition from an outside row is most detrimental to adjacent rows was determined in the third study by removing the outside row at various stages. Competition near the silking period was most detrimental since nutrient uptake and dry matter accumulation are rapid near this time and kernel number is being determined.
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