Milestones in Agriculture

In the mid 19th century, German chemist, Justus von Liebig, later dubbed “the father of chemical agriculture”, analysed the ashes of a plant and deduced that, as the major elements present were nitrogen, phosphorus and potassium (The N-P-K of modern agriculture), then these must be the principle elements required for plant growth. Before von Liebig’s discovery it was believed that humus was the major source of nourishment for plant growth. Von Liebig attacked the humus theory vehemently and was able to successfully convince European academics that his simplistic three-element nutrition plan was the “one true way” for any rational scientific community. Von Liebig’s “Chemistry in its Application to Agriculture” was to have such an impact that it still stands as the turning point, where scientific agriculture jettisoned the concept of working with natural processes and cycles, in favour of planned intervention and man-made solutions. Big business, as could be expected, was never far from the state-of-play.
For centuries farmers had controlled their own destiny, nursing and nourishing their soils with techniques of time-honoured tradition. In what seemed a stroke of von Leibig’s pen, that situation changed forever. The principle inputs for food production were now to be purchased from outside the farm gate. Nitrate beds from Chile, potash mines from Germany and American phosphate deposits were sources for the initial N-P-K rush, but in a few short years chemical companies had begun to process and synthesise “the big three”. The profits in providing these new “essential” commodities, on a world stage, were stupendous. It was no surprise that, when a humbled von Leibig announced ten years later that he had made a huge mistake, his confession was completely ignored. Von Liebig had realised that a large part of the initial response to N-P-K fertilising was actually derived from the release of nutrients from the gradual breakdown of the humus component of the soil. An oversupply of nitrogen was triggering a microbe feeding frenzy, and the overstimulated organisms were devouring organic carbon. The N-P-K approach was actually mining the humus from the soil. Von Liebig had realised that the N-P-K goldrush was a fool’s paradise, which could not be sustained. However, the wheels of big business were oiled and rolling, and nothing was going to stop them. Von Liebig’s new findings vanished without trace. For all intents and purposes, that juggernaut has continued unabated for one and a half centuries since von Liebig’s mistake.

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