The Ground Beneath the Crop

Edmund Ruffin, born in 1794, recommended crop rotation and amendments to restore soils worn out by tobacco monoculture, and is called the father of soil science in the United States. His page also records his role as an early advocate of secession and a defender of slavery, so he enters the path with both facts attached.

Justus von Liebig, born in 1803, established that plants feed on mineral nutrients such as nitrogen, phosphorus and potassium rather than on humus itself. His law of the minimum, that growth is limited by the scarcest nutrient, is why he is called the father of the fertilizer industry.

Eugene W. Hilgard, a German-American born in 1833, is regarded as the father of modern soil science in the United States. He studied climate as a soil-forming factor, soil chemistry and the reclamation of alkali soils, and helped make the study of soil resources a discipline of its own.

Vasily Dokuchaev, born in 1846, is commonly regarded as the father of soil science. He studied soils in their natural setting and built the first classification based on climate, vegetation, parent material, topography and time, treating soil as a natural body rather than broken rock.

Franklin Hiram King, born in 1848, taught agricultural physics at the University of Wisconsin-Madison and is called the father of soil physics in the United States for his work on soil water and aeration. He is also remembered for Farmers of Forty Centuries, his account of traditional farming in China, Korea and Japan.

Curtis F. Marbut, born in 1863, directed the Soil Survey Division of the U.S. Department of Agriculture from 1913 until his death in 1935. He developed the first formal soil classification scheme for the United States, shaped by Hilgard and by his translation of Konstantin Glinka.

Fritz Haber, born in 1868, synthesized ammonia from atmospheric nitrogen in 1909, the step that made manufactured fertilizer possible and that now helps feed about half of humanity. His page carries the other side of his career, his direction of Germany's chemical weapons program in the First World War.

Carl Bosch, born in 1874, took Haber's laboratory process to industrial scale as the Haber-Bosch process. It is estimated that one-third of annual global food production uses ammonia from it, which is why his work sits beside the soil scientists on this path.

Albert Howard, born in 1873, was an English botanist who, working in India, was the first Westerner to document and publish Indian techniques of sustainable agriculture. He became a principal figure in the early organic movement, with Eve Balfour.

Selman Waksman, born in 1888, studied the decomposition of organisms that live in soil, research that enabled the discovery of streptomycin and other antibiotics and won him the 1952 Nobel Prize in Physiology or Medicine.

William A. Albrecht, born in 1888, chaired the Department of Soils at the University of Missouri and tied soil fertility to the health of livestock and people. He developed the Base Cation Saturation Ratio, a formula for ideal ratios of cations in soil.

J. I. Rodale, born in 1898, was a publisher who founded Rodale, Inc. and the Rodale Institute, originally the Soil Health Foundation. He popularized the term organic for growing food without pesticides and helped launch the American organic farming movement.

Masanobu Fukuoka, born in 1913, was a Japanese farmer and philosopher who developed natural farming, also called do-nothing farming, a no-till method free of herbicides and pesticides. He closes the path with the most hands-off approach to soil on it.