Translations:Manfred Klett: Von der Agrartechnologie zur Landbaukunst/231/en

of a farm lose as many nutrients as are contained in the crops sold off it. From this conclusion he founded his mineral fertiliser theory, according to which the nutrient present in minimum quantity limits the yield. Liebig — who stood with one foot still in German Idealism and with the other in the rising materialism of the second half of the nineteenth century — was convinced that the loss of the soil-bound core nutrients, phosphorus, potassium, and others, must be replaced in the soil through manuring. He judged differently, in opposition to the prevailing doctrine, regarding nitrogen: for this, nature itself would have to provide. Set against him were his opponents, the advocates of nitrogen fertilisation, who in the course of time gained the upper hand. A posthumous vindication for Liebig was the realisation and confirmation of his theses by the farmer Schultz-Lupitz (1831–1899), who, after decades of endeavour, succeeded in significantly improving the yield level of the extremely poor sandy soils of Lupitz by deepening the humus profile.