Abstract
FOR some years past the United States Department of Agriculture Bureau of Soils has maintained that infertility might, and not unfrequently does, arise from the presence in the soil of toxic organic substances that have been excreted from the roots of plants. This view has been opposed on two grounds: it is not evident that plants do normally excrete poisonous substances; and if such substances are present there is no proof that they would act as poisons in the soil, which possesses a remarkable power of withdrawing dissolved substances from solution. Not long ago Schemer isolated dihydroxystearic acid from a considerable number of unproductive soils, and now, in conjunction with J. J. Skinner,1 he has examined its behaviour to plants in water cultures. In all cases its effect was toxic, but the toxicity was much reduced when fertilisers were added to the solution, and was at a minimum when the fertilising constituents were present in the ratio most favourable to plant growth. Several incidental questions were also cleared up dealing with water cultures-perhaps the most difficult of all experiments to interpret—and the paper contains a great number of data bearing on the subject. The behaviour of this acid in the soil is not touched upon, and very wisely no attempt is made to argue from a water culture to a soil. It is, however, a distinct step in advance that an acid has been isolated from certain soils and identified, and shown to be poisonous in water culture. The results may well be connected with the known fact that, in absence of lime, soil becomes acid and loses fertility, which can only be restored by addition of lime or chalk.
Article PDF
Rights and permissions
About this article
Cite this article
RUSSELL, E. Recent Investigations on Soil Fertility . Nature 86, 363–364 (1911). https://doi.org/10.1038/086363a0
Published:
Issue Date:
DOI: https://doi.org/10.1038/086363a0