Aluminum in the soil solution is a severe growth limiting factor in certain acid soils (Foy, 1964; Long and Foy, 1970). This problem is particularly serious in acid subsoils (Adams and Lund, 1966; Foy, 1964) which are difficult to lime. Recent research has centered on selecting those plant cultivars which demonstrate a degree of tolerance to soil aluminum.
Devine, T. E.; Foy, C. D.; Mason, D. L.; and Fleming, A. L.
"Research notes: Aluminum tolerance in soybean germplasm,"
Soybean Genetics Newsletter: Vol. 6
, Article 13.
Available at: http://lib.dr.iastate.edu/soybeangenetics/vol6/iss1/13