Effect of Soil Al Saturation on Nutrient Concentration of Soybean Tops, Roots, and Nodules1
- J. B. Sartain and
- E. J. Kamprath2
A small amount of information is available on the effects of Al saturation on the nutrient concentration of different plant components. This manuscript presents data showing the former relative to the soybean [Glycine max (L.) Merr.]. To study the effects of varying exchangeable Al saturation on the concentration of P, Ca, Mg, and A1 in the tops, primary roots, lateral roots, and nodules of soybeans, a randomized complete block greenhouse experiment using 12 soybean cultivars and three soil AI saturation levels was established. The soil was a Lynchburg sandy loam (Aeric Ochraquult). Soil Al saturation levels were established by adding various amounts of lime. Soil Al saturation had no effect on the P concentration of the tops. Root P concentration was significantly higher at 81% Ai saturation than at 28 and 4%. Nodules bad a much higher P concentration than the other plant parts. The calcium concentration of all plant parts was increased with increasing additions of CaCO3. Tops contained the highest Ca concentration and nodules the lowest. Aluminum saturation levels of 81 and 28% did not significantly affect the Mg concentration of the tops and primary roots. The Mg concentration of the nodules decreased as AI saturation decreased due primarily to a dilution effect. Tops and nodules contained approximately twice as much Mg as the root components. Top and root Al concentration was reduced by 53 and 30%, respectively, when the Al saturation was reduced from 81 to 28%. Aluminum concentration of tops was 6, 2, and 8% of the primary roots, lateral roots, and nodules, respectively at 81% Al saturation. Top growth and nodule number increased as the Al saturation was reduced from 28 to 4%, however, very little change occurred in the Al concentration of the tops over this range. Thus, growth responses of soybeans to reduction of soil Al saturation below 28% appears to be due to pH effects and/or Ca supply.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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