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Yield Response of Alfalfa Cultivars and Clones to Several pH Levels in Tatum Subsoil 1
Author(s) -
Buss G. R.,
Lutz J. A.,
Hawkins G. W.
Publication year - 1975
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/agronj1975.00021962006700030012x
Subject(s) - cultivar , subsoil , agronomy , forage , soil water , biology , soil ph , yield (engineering) , horticulture , ecology , materials science , metallurgy
Breeding for increased tolerance to high aluminum‐low pH soils should enlarge the range of adaptation of alfalfa ( Medicago sativa ). This research was undertaken to obtain information on the range of genetic variation present in alfalfa cultivars for reaction to soil pH in a high aluminum soil. Eighteen alfalfa cultivars were planted in unlimed (pH 4.4) and limed (pH 6.0) Tatum (Typic Hapludults, clayey, mixed, thermic) subsoil. None survived in the unlimed soil and all grew in the limed soil. Clones were selected for root development in unlimed soil after growing down through a 5 cm layer of limed soil. When grown at pH levels of 5.3, 6.1, and 7.5, they showed a highly significant clone × pH interaction for yield. However, on the average they did not seem much more acid tolerant than unselected clones. This screening technique was somewhat successful in isolating acid tolerant clones, but forage yield at low pH appeared to be a better criterion. Our results indicate that alfalfa cultivars exhibit a narrower range of acid tolerance than is known to exist in several other crop species, but that individual clones differ in their reaction to both low and high soil pH. We concluded that sufficient genetic variation exists to permit selection for tolerance to low pH, but the narrow genetic base might limit progress. Also the overall adaptation of selected populations might be somewhat unpredictabe because of the clone × pH interaction.