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Yield of an Alfalfa Germplasm Selected for Acid Soil Tolerance when Grown in Soils with Modified Subsoils 1
Author(s) -
Bouton J. H.,
Sumner M. E.,
Hammel J. E.,
Shahandeh H.
Publication year - 1986
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1986.0011183x002600020025x
Subject(s) - subsoil , germplasm , agronomy , topsoil , soil water , yield (engineering) , environmental science , biology , soil science , materials science , metallurgy
Liming and fertilization are required to enhance alfalfa ( Medicago sativa L.) yield in acid soils, but rarely do these practices overcome the problem of subsoil acidity. Genetic selection of alfalfa for acid soil tolerance (especially Al tolerance) is felt to be a good method of increasing alfalfa's rooting into acid subsoils resulting in better water and nutrient extraction and, finally, better yield and persistence. In this study, the yield of an alfalfa germplasm selected for acid soil tolerance was compared with that of a germplasm concurrently selected in a limed, fertile soil and the cultivar Apollo. These were tested in the field using the following subsoil treatments: i) an unlimed, unmixed control subsoil, ii) sub‐soil mixed to 1 m, iii) subsoil mixed and limed to 1 m, and iv) gypsum incorporated into the surface to leach into the subsoil. The topsoils were all conventionally limed and fertilized. Overall, deep liming and gypsum additions to the topsoil increased alfalfa yield over the control. The acid soil selected germplasm gave better yield than the limed soil selected germplasm when data were averaged for all subsoil treatments. The acid selected germplasm was significantly higher yielding than the limed selected germplasm in the mixed and limed subsoil treatment and in the mixed subsoil treatment. The mixed subsoil treatment was also found to be the most acid, Al toxic treatment. However, the acid tolerant germplasm was no different in yield from Apollo in the mixed subsoil treatment, and in the control treatment, the acid germplasm gave poorer yield than the limed soil selected germplasm. These data demonstrate acid subsoil problems are severe in reducing yield, but can be overcome with deep liming or gypsum amelioration or, possibly, with more tolerant cultivars.