THE TOLERANCE LIMIT OF SEEDLINGS FOR ALUMINUM AND IRON AND THE ANTAGONISM OF CALCIUM

Abstract

With the the condition and growth of the radicals of Lupinus albus and Phaseolus vulgaris nanus as criteria, the relative toxicity of Fe and Al to these plants and to each other was studied. Data show the increased toxicity of Al and Fe at 29[degree] C. L. albus is about 3 times as resistant to Al and Fe as is Phaseolus. The Fe ion is about 5-7 times as toxic as the H ion. The antagonism of Ca for Al and Fe is demonstrated, and from these data the limits of Al and Fe concentration that may exist in the. soil solution are approximated for L. albus and for Phaseolus. Pot experiments were used to check water culture conclusions. Experiments and citations are discussed in support of the opinion that p H of itself is of little importance as an ecologic factor.