This paper traces two stories of agriculture that merged in late autumn 1944 on a lettuce field in California's Salinas Valley. On that field, two transmuted industrial waste products from California's rudimentary petroleum economy were at once injected into the soil and into agricultural production, spurring a radical transformation of crop rotation and recasting the organizational possibilities of industrial agriculture. Taken together, these stories tell a tale of capital and chemistry overcoming an ecological contradiction of agro-industrialization. This paper considers an earlier history of petroleum-based agrochemicals, situating their development in the interwar years and within the context of California's emerging petroleum complex. It argues that, in the late 1920s, agriculture began its transformation into a new and immensely productive agricultural regime organized around the oil industry and its waste byproducts. The petrochemicals and subterranean chemical warfare that were developed during this time became industrial agriculture's chemical salvation, providing both the soil disinfection power and the soil nutrition that made the massive yield increases in agricultural production following World War II possible.