Passage:
For several decades following the publication of Justus von Liebig’s influential Die organische Chemie in ihrer Anwendung auf Agricultur und Physiologie in 1840, agricultural science operated under the premise of the "mineral theory." Liebig asserted that plants absorbed all necessary nutrients, including nitrogen, exclusively as inorganic compounds from the soil, dismissing atmospheric nitrogen as a biological nutrient source. Consequently, soil exhaustion was framed primarily as a depletion of mineral salts, which could be remediated solely through chemical fertilizers. This paradigm was challenged in the late 1880s by the research of Hermann Hellriegel and Hermann Wilfarth, who demonstrated that leguminous plants possessed the unique capacity to fix atmospheric nitrogen via root nodule symbiosis with soil micro-organisms. Rather than merely replacing mineral depletion through artificial additions, Hellriegel and Wilfarth revealed an intricate biological interplay between plants and soil microbiota that fundamentally altered the understanding of nutrient cycling. While subsequent historians have often framed Hellriegel and Wilfarth’s findings as a sudden, revolutionary collapse of chemical agrarianism, closer analysis of contemporary scientific discourse suggests a more gradual paradigm shift. Nineteenth-century agronomists had long observed the restorative effects of crop rotation with legumes; Hellriegel and Wilfarth provided the mechanistic explanation for a traditional practice rather than overthrowing established agricultural utility outright. Thus, their work re-contextualized existing empirical traditions within a microbiological framework rather than instigating a complete repudiation of prior soil science.
Which of the following best expresses the primary purpose of the passage?
- To evaluate the transition from Liebig's mineral theory to microbiological soil science by arguing that new discovery mechanistic explanations contextualized rather than abruptly subverted traditional agricultural practices.Answer
- BTo describe the precise biochemical pathways by which root nodule micro-organisms convert atmospheric nitrogen into usable plant nutrients.
- CTo denounce nineteenth-century chemical agriculture as an erroneous doctrine that hindered legitimate biological research into crop rotation.
- DTo demonstrate that early agronomists abandoned traditional empirical methods immediately following the introduction of Liebig's mineral theory.
- ETo argue that modern synthetic fertilizer production should be replaced entirely by leguminous biological nitrogen fixation.