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Preemergent Shoot Growth of Maize under Different Drying Conditions
Author(s) -
Weaich Karl,
Bristow Keith L.,
Cass Alfred
Publication year - 1992
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1992.03615995005600040044x
Subject(s) - shoot , agronomy , elongation , coleoptile , soil water , arid , environmental science , horticulture , water content , chemistry , biology , soil science , botany , materials science , ultimate tensile strength , geology , ecology , geotechnical engineering , composite material
Abstract Poor establishment of seedlings is a problem in semi‐arid cropping regions. High drying rates that are characteristic of these regions can result in the early onset of high soil strengths and high soil temperatures, which are detrimental to seedlings. In this study, we examined the response of preemergent shoot growth of maize ( Zea mays L.) to differences in the drying rate of a hardsetting red‐brown earth (fine, mixed, thermic Typic Paleustalf or Calcic Luvisol). We examined the impact of high soil strength on the constituent shoot parts (coleoptile and first internode), and used a temperature‐based shoot‐growth model to separate the effects of soil temperature and soil strength on preemergent shoot growth. Preemergent shoot growth was sensitive to small differences in drying rate. Rapid drying resulted in no emergence, moderate drying in 52% emergence, and slow drying in 78% emergence. Soil strength impeded shoot elongation at a cone index of 1.1 MPa and, at 2 MPa, growth and emergence ceased. Differences in soil strength development reflected not just the total amount of water removed from the profile, but also the distribution of water remaining within the profile. Rapid drying quickly reduced soil water content near the surface and led to the immediate development of high soil strength there. Reduction in shoot elongation at high soil strengths was largely due to the sensitivity of the first internode. The coleoptile elongation rate showed no response to treatment differences in soil strength although twisting, buckling, and rupture was more prevalent at high soil strengths.