The Great Humus Debate

From von Liebig to the present, what humus is — and what it can do for farmers — continues to be debated

If there were ever two figures from history who should have crossed paths, it would have been Sir Albert Howard and Justus von Liebig. Despite living in different eras, they both approached the subject of soil humus with passion and skill, seemingly on opposite ends of the spectrum. However, a fresh look offers a different perspective, revealing insights into the inconsistencies in humus revolutions and the origins of organic farming.

Justus von Liebig (1803-1877) is widely recognized for pioneering the “Mineral Theory” — that the essential nutrients for plants are inorganic minerals. This theory contributed to the transition from traditional agricultural methods such as crop rotations and manuring to what is commonly referred to as “chemical farming.” Liebig’s influence is often criticized in contemporary organic farming literature, beginning with Howard. However, delving into Liebig’s extensive body of work presents a challenge in discerning which ideas to embrace and which to question.

Sir Albert Howard (1873-1947) is widely thought of as the father of organic farming. Coming after Liebig, he occasionally expressed admiration for his work, characterizing it as a “great advance,” “vast,” and “illuminating,” noting that Liebig was “a pioneer not only in science, but in practice.” But in his later years, after returning to England from service in British-India, Howard became outspoken in condemnation of Liebig’s legacy, which had taken strong root in England. In an important way, Howard established the now well-worn contrast of “chemical vs organic” farming.