Question

In his 1840 treatise on organic chemistry applied to agriculture, Justus von Liebig posited that plant growth is limited not by the abundance of organic humus in the soil, but by the relative scarcity of specific inorganic minerals. To address soil degradation, Liebig advocated the application of artificial mineral fertilizers to replace depleted salts. However, when early field trials of his synthesized manures yielded disappointing results, contemporary agronomists attributed the failure to the insolubility of the chemical preparations, which prevented crop roots from absorbing the essential nutrients. In responding to these critiques, Liebig argued that the apparent failure stemmed not from chemical defects in the fertilizers themselves, but rather from the improper cultivation practices of farmers who neglected soil aeration. He asserted that without adequate tillage, the mineral salts could not react effectively with soil moisture, rendering them inert. This oversight, Liebig maintained, perpetuated the very exhaustion that his mineral formulation was engineered to reverse.

In the passage, the phrase "This oversight" in the final sentence refers to which of the following?