Beyond the Field: DCF Alumni Share Their Stories

Secret Nitre Lurks Within”: Intermixing Soil and Georgics

By: Jane Harwell

I started off my summer research as a Farm Fellow with a driving question: how can a reading of poetry and a study of land enrich one another? In the current Duke Forest, there is a tract of land that is the site of an eighteenth-century farm once owned by the Couch family. On this land, an excavation site shows layers of contact between humans and soil called horizons. Part of the way human interaction with land is made distinct is through the levels of nitrogen still present. It was around this time that I started noticing the word “nitre” appearing in eighteenth-century British poetry. The first place I noticed it was in James Thomson’s The Seasons (1730). The poem “Winter” reads, “For sight too fine, th’ etherial Nitre flies;/ Killing infectious Damps, and the spent Air/ Storing afresh with elemental Life” (695-697). The “etherial Nitre” that presents in Winter is realized in “Autumn,” as the poem opens, “…Whate’er the wintry frost/ Nitrous prepar’d; the various-blossom’d Spring/ Put in white promise forth” (4-8). Thomson posits that nitre from the air prepares the soil for Spring growth. Nitrogen wasn’t formally identified until 1774 by Scottish scientist Daniel Rutherford, so I wanted to find out what “nitre” meant at the time of Thomson’s writing.

Nitre is defined in Samuel Johnson’s formative Dictionary as a “number of those salts which are naturally blended in imperceptible particles in earths, stones, and other fossile substances.” Early agriculture manuals, or husbandry guides, also attempt to define nitre, occasionally referring to it as an element in the soil, sometimes in the air, other times it is in water or frost. Sometimes nitre is inherently within the soil, other times it is a manufactured salt farmers produce using their own pigeon coops; other definitions note that nitre cannot be manufactured in England and must be imported from France or warmer climates. The only common theme between all of the definitions of nitre is that it is necessary for the growth of plants. Eighteenth-century British poetry picked up the agricultural term and used nitre as part of a poetic vocabulary. During this time, there was also a rise to didactic poetry resembling Virgil called georgics. Georgics overwhelmingly adapt information from husbandry guides, including the uses of nitre which feature in many eighteenth-century georgics.

The popularity of georgics mentioning nitre established a precedent for valuing nitre as a central component to soil preparation. This model led to the use of nitrogen in commercial fertilizers, which dramatically increase the presence of reactive nitrogen culminating in acid rain, smog, coastal eutrophication, the greenhouse effect, climate change, and the stratospheric ozone depletion. The site of the Couch farm in Duke Forest materially reminds us of the impact of Anthropogenic activities, as the soil reflects increased nitrogen in the horizons of human interaction.