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Root Development of Sericea Lespedeza and Alfalfa in Acid Soils 1
Author(s) -
Joost R. E.,
Hoveland C. S.
Publication year - 1986
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1986.00021962007800040030x
Subject(s) - taproot , agronomy , seedling , root system , lespedeza , loam , shoot , subsoil , soil water , chemistry , mollisol , soil horizon , horticulture , biology , environmental science , soil science
A more thorough understanding of sericea lespedeza [ Lespedeza cuneata (Dum.) G. Don] root system development is needed to improve management of seedling stands during establishment, especially in acid subsoils, which often limit root development of legumes. A greenhouse experiment was conducted using glass‐front root boxes to quantify seedling root system development of five lines of sericea lespedeza and ‘Apollo’ alfalfa ( Medicago sativa L.) in acid (high AI and Mn) and limed soil layers underlying limed surface soil. The root boxes were partitioned into six 12.5 cm by 12.5 cm by 80 cm deep sections and each section was packed with Bradson clay loam (clayey, oxidic mesic Typic Hapludults) topsoil. Root growth rate (GR) and rooting intensity (cm cm −2 viewing surface) were monitored by tracing daily root growth on mylar sheets covering the glass front of the boxes. Measurements of root GR in limed subsurface soil indicated that alfalfa taproots elongated at twice the rate of the sericea entries evaluated. Alfalfa root GR was reduced by 69% in unamended soil, whereas root GR was not reduced in three sericea lines in the unamended treatment. Rooting intensity of 0.79 in alfalfa was twice that of sericea; however, in acid soil, abnormally branched and swollen secondary roots represented a large portion of the alfalfa root system. In addition, secondary taproot growth (thickening) in alfalfa was reduced 30% in both the surface and subsurface soil of the unlimed treatment. Root/shoot ratios based on root length in limed subsoil indicated that sericea produces more root growth per unit shoot than alfalfa.