Corn Seedling Root Growth as Influenced by Soil Physical Properties1
- S. D. Logsdon,
- R. B. Reneau and
- J. C. Parker2
Management practices often affect soil physical properties adversely thus reducing root growth. In the field difficulty arises in determining which soil physical property is influencing root growth because the factors are not readily separated. The purpose of this study was to examine the effects of isolated soil physical factors on corn (Zea mays L.) seedling growth under controlled conditions. Corn was grown in A horizon material of Groseclose silt loam (clayey, mixed, mesic Typic Hapludult) at four bulk densities (1.10, 1.22, 1.35, and 1.47 Mg/m3), four lower soil moisture levels (0.24, 0.21, 0.18, and 0.15 m3/m3), four higher soil moisture levels (0.24, 0.27, 0.30, and 0.33 m3/m3), and three temperatures (25, 21, and 17°C) in growth chamber experiments. Optimal conditions as indicated by maximum root elongation for corn in Groseclose silt loam occurred with volumetric moisture contents from 0.24 to 0.27 m3/m3, bulk densities <1.22 Mg/m3, and a temperature of approximately 25°C. High bulk density, oxygen stress, low temperature, and water stress all reduced root elongation to some extent. Low temperature had the most dramatic effect. At 6 days corn root length at 21°C was only about 20% of that at 25°C, whereas root length at 17°C was only about 5% of that at 25°C. As bulk density increased, root length decreased. After 4 days high soil moisture stimulated root growth. Root length was not reduced by low soil moisture except at the lowest level (equivalent to a matric potential of −1090 kPa).Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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