Thomas Jefferson: Agronomist
In his own eyes, Thomas Jefferson considered himself first and always a man of the land. He felt that "those who labour in the earth are the chosen people of God...." What made Jefferson unique in his time was his understanding of the interrelationship between humanity and the environment and how they shaped each other. This wisdom and his subsequent practices, such as crop rotation, use of fertilizer, and contour plowing, characterize him as one of America's early agronomists.
Jefferson was one of the first Americans to realize that the bounty of this continent was finite. If the nation and its citizens were to continue to enjoy the fruits of the New World, then its resources must be husbanded with proper stewardship.
In Jefferson's era comparatively few farmers were concerned with returning any vital elements back to the earth by methods such as cropping, crop rotation, and fertilizers. In fact, the Virginia Piedmont of his time was already played out by adverse agricultural practices. In the short span of years that the area was opened for European use, tobacco had become the chief crop; this, combined with corn, the staple food crop, had taken a heavy toll on the productive land. Erosion and soil exhaustion followed the pioneers as sloping land was cleared of natural vegetation and continuously planted with the same crops.
Under this endless sequence of tobacco and corn, planted in rows that usually ran up and downhill, much of the virgin topsoil had been lost by Jefferson's time. "The highlands where I live have be cultivated about sixty years. The culture was tobacco and Indian corn long as they would bring enough to pay the labour. Then they were turned out...
Jefferson was concerned not only with current return from the land but also with the effects of land abuse on posterity. Unlike his contemporaries, he knew that the productive land of the United States was not infinite. He acknowledged the prevailing attitude of his day in a letter to George Washington in 1793. "...we can buy an acre of new land cheaper than we can manure an old acre." Therefore, he was in the forefront in experimenting with fertilizers to bring his land back to productivity.
Not content to assume that animal manure would revitalize the soil, he undertook tests to determine the exact number of cattle required to fertilize a given area of land. He measured its effectiveness by comparing yields of grain on manured fields with yields from an equal area that was unfertilized.
Jefferson was one of the first Americans to propound crop rotation as a way of renewing the soil. He devised an extensive seven-year plan for his land, as follows:
- Wheat, followed the same year by turnips, to be fed to the sheep.
- Corn and potatoes mixed, and in autumn the vetch to be used as fodder in the spring if wanted, or to be turned in as a dressing.
- Peas or potatoes, or both according to the quality of the fields.
- Rye and clover sown on it in the spring. Wheat may substituted here for rye.
- Clover, and in autumn turn it in and sow the vetch.
- Turn in the vetch in the spring, then sow buckwheat and turn that in, having hurled off the poorest spots for cowpenning, (so these spots could be improved by the manure).
He used this rotation system with legumes and grasses in an attempt to bind the soil against washing out, to improve his hard-used land, and to arrive at the best fit between the environment and plant.
Jefferson was in the forefront in developing scientific plowing in the infant United States. The plows of his time were crude tools made of wood that would barely scratch the soil. This shallow plowing merely loosened the topsoil making it susceptible to washing away at the first hard rain. To counteract this problem Jefferson developed his moldboard plow of "least resistance," which lifted and turned the sod. With this tool he could plow to a depth of about six inches. This enabled farmers to contour-ridge erodible fields, plow out shallow ditches, and ridge poorly drained flat lands.
Jefferson was one of the first to utilize his plow in horizontal or contour plowing and proselytized this method to fellow farmers in the following 1813 account to Charles Peale:
Our country is hilly and we have been in the habit of plouhing in straight rows whether up and down, in oblique lines, or however they lead; and our soil was rapidly running into rivers. We now plough horizontally, following the curvatures of the hills and hollows, on the dead level, however crooked the lines may be. Every furrow thus acts as a reservoir to receive and retain the waters, all of which go to the benefit of the growing plant, instead of running off into the streams. In a farm horizontally and deeply ploughed, scarcely an ounce of soil is now carried off from it.
Jefferson's bench terraces for his vegetable garden, orchard, and vineyard sites have the appearance of land that his long been contoured. He also knew the value of native ground cover in stopping erosion, instructing his overseer to conserve timber by "never cutting down a tree for firewood or any other purpose as long as one can be found ready to cut down..."
Jefferson searched constantly for new crops adapted to his conditions of land and climate. While United States envoy to France, he sent seeds of various grasses, acorns of the cork oak, olive plants and innumerable fruits and vegetable seeds to agricultural societies, farmers, and botanist in the infant United States. It is said that his gift of Italian rice, which he smuggled out of Italy, to the planters of South Carolina enabled them to produce the best rice in the world. He brought to the eastern United States the "Paccan Tree," which grew "on the Illinois, Wabash, Ohio, and Mississippi," and distributed it throughout Virginia. He is credited with introducing a variety of now-common vegetables to America, among them Brussels sprouts, eggplant, cauliflower, and broccoli.
It is evident that Jefferson considered such activity of supreme importance. He stated:
The greatest service which can be rendered any country is to add a useful plant to its culture...One such service of this kind rendered to a nation is worth more to them than all the victories of the most splendid pages of their history, and becomes a source of exalted pleasure to those who have been instrumental in it
Jefferson encouraged agricultural societies as a means of spreading good stewardship of the land. He also vigorously supported sound conservation and agricultural education and investigation at the university level.
It is a science of the first order...It counts among its handmaids the most respected sciences, such as Chemistry, Natural History, Botany. In every College and University, a professorship of agriculture, and the class of its students, might be honored as first.
Jefferson's own gardens were his laboratory, where he experimented with dozens of species. He cultivated 170 varieties of fruits and 330 different kinds of vegetables, including 40 types of beans, two dozen kinds of English peas, and 17 types of lettuce. He kept extensive farm journals from 1767 to 1824. These meticulous records detailed when plants were sown, sprouted and harvested. There is a record, in one; of him counting the number of peas that would make a pint, which was 2,500. This arduous task allowed him to determine the number of rows of peas that a pint of seeds would produce. To Jefferson no task concerning agronomy was mundane. It was one of his great joys in life. He wrote: "No occupation is so delightful to me as the culture of the earth and no culture comparable to that of the garden."
He also experimented with viniculture and the brewing of beer. Wine was his preferred drink and he saw beer and ale as a food. As usual, he took a scientific approach toward these ventures.
I see too with great satisfaction every example of bending science to the useful purposes of life. Hitherto chemistry has scarcely deigned to look to the occupations of domestic life. When she shall have made intelligible to the ordinary householder the philosophy of making bread, butter, cheese, soap, beer, cyder, wine, vinegar etc. these daily comforts will keep us ever mindful of our obligations to her. The art of distilling which you propose to explain, besides its household uses, is valuable to the agriculturalist, as it enables him to put his superfluous grain into a form which will bear long transportation to markets to which the raw material could never get.
Many of Jefferson's ideas about government, which are the philosophic underpinnings for our country, are based on the interrelationship between the land and the people. He clearly felt that the closer people were to the land, the freer they were to lead more "natural" lives and thus experience more directly the full possession of their natural unalienable rights. And in the process they might also feel closer to their God, the source of those rights.
At the center of Jefferson's vision of the United States stood the educated, yeoman farmer. An enlightened citizen, trained in many fields, was the only force that Jefferson felt could maintain our democracy and the land upon which it was based. This natural educated man was the basis of stability in government, the basis of true morality, and the basis of the country's freedom. Therefore, in Jefferson's view, proper stewardship of the land was vital if the infant United States were to survive.
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