Liebig, BaronJustus von

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Liebig, BaronJustus von (1803–73)A German chemist who contributed much to the systematization of organic chemistry, the early development of biochemistry, and agricultural chemistry. In 1840 he published Die organische Chemie in ihrer Anwendung auf Agrikulturchemie und Physiologie (‘Organic Chemistry in its Application to Agricultural Chemistry and Physiology’), in which he showed that plants take up nutrients in simple chemical form and that nutrient deficiencies in soils may be remedied by the application of mineral fertilizers. He maintained that plant growth is limited by the availability of the scarcest essential nutrient (see Liebig's law of the minimum). Others expanded on this work later to produce a broader appreciation of the ‘limits of tolerance’, recognizing that maximum as well as minimum thresholds exist for all commodities (not only chemicals) that are essential to plant and animal growth. See also Shelford's law of tolerance.