To Tristam Dalton Monticello, May 2, 1817

The Letters of Thomas Jefferson DEAR SIR,

-- I am indebted to you for your favor of Apr. 22, and for the copy of the Agricultural magazine it covered, which is indeed a very useful work. While I was an amateur in Agricultural science (for practical knolege my course of life never permitted me) I was very partial to the drilled husbandry of Tull, and thought still better of it when reformed by Young to 12 rows. But I had not time to try it while young, and now grown old I have not the requisite activity either of body or mind.

With respect to field culture of vegetables for cattle, instead of the carrot and potato recommended by yourself and the magazine, & the best of others, we find the Jerusalem artichoke best for winter, & the Succory for Summer use. This last was brought over from France to England by Arthur Young, as you will see in his travels thro' France, & some of the seed sent by him to Genl. Washington, who spared me a part of it. It is as productive as the Lucerne, without its laborious culture, & indeed without any culture except the keeping it clean the first year. The Jerusalem artichoke far exceeds the potato in produce, and remains in the ground thro' the winter to be dug as wanted. A method of ploughing over hill sides horizontally, introduced into the most hilly part of our country by Colo. T. M. Randolph, my son in law, may be worth mentioning to you. He has practised it a dozen or 15 years, and it's advantages were so immediately observed that it has already become very general, and has entirely changed and renovated the face of our country. Every rain, before that, while it gave a temporary refreshment, did permanent evil by carrying off our soil: and fields were no sooner cleared than wasted. At present we may say that we lose none of our soil, the rain not absorbed in the moment of it's fall being retained in the hollows between the beds until it can be absorbed. Our practice is when we first enter on this process, with a rafter level of 10 f. span, to lay off guide lines conducted horizontally around the hill or valley from one end to the other of the field, and about 30 yards apart. The steps of the level on the ground are marked by a stroke of a hoe, and immediately followed by a plough to preserve the trace. A man or a lad, with the level, and two small boys, the one with sticks, the other with the hoe, will do an acre of this in an hour, and when once done it is forever done. We generally level a field the year it is put into Indian corn laying it into beds of 6 ft. wide, with a large water furrow between the beds, until all the fields have been once leveled. The intermediate furrows are run by the eye of the ploughman governed by these guide lines, & occasion gores which are thrown into short beds. As in ploughing very steep hill sides horizontally the common ploughman can scarcely throw the furrow uphill, Colo. Randolph has contrived a very simple alteration of the share, which throws the furrow down hill both going and coming. It is as if two shares were welded together at their straight side, and at a right angle with each other. This turns on it's bar as on a pivot, so as to lay either share horizontal, when the other becoming verticle acts as a mould board. This is done by the ploughman in an instant by a single motion of the hand, at the end of every furrow. I enclose a bit of paper cut into the form of the double share, which being opened at the fold to a right angle, will give an idea of it's general principle. Horizontal and deep ploughing, with the use of plaister and clover, which are but beginning to be used here will, as we believe, restore this part of our country to it's original fertility, which was exceeded by no upland in the state.

Believing that some of these things might be acceptable to you I have hazarded them as testimonials of my great esteem & respect.