A sketch of the history of dry-farming would be incomplete without a mention of the life and work of Jethro Tull.  The agricultural doctrines of this man, interpreted in the light of modern science, are those which underlie modern dry-farming.  Jethro Tull was born in Berkshire, England, 1674, and died in 1741.  He was a lawyer by profession, but his health was so poor that he could not practice his profession and therefore spent most of his life in the seclusion of a quiet farm.  His life work was done in the face of great physical sufferings.  In spite of physical infirmities, he produced a system of agriculture which, viewed in the light of our modern knowledge, is little short of marvelous.  The chief inspiration of his system came from a visit paid to south of France, where he observed “near Frontignan and Setts, Languedoc” that the vineyards were carefully plowed and tilled in order to produce the largest crops of the best grapes.  Upon the basis of this observation he instituted experiments upon his own farm and finally developed his system, which may be summarized as follows:  The amount of seed to be used should be proportional to the condition of the land, especially to the moisture that is in it.  To make the germination certain, the seed should be sown by drill methods.  Tull, as has already been observed, was the inventor of the seed drill which is now a feature of all modern agriculture.  Plowing should be done deeply and frequently; two plowings for one crop would do no injury and frequently would result in an increased yield.  Finally, as the most important principle of the system, the soil should be cultivated continually, the argument being that by continuous cultivation the fertility of the soil would be increased, the water would be conserved, and as the soil became more fertile less water would be used.  To accomplish such cultivation, all crops should be placed in rows rather far apart, so far indeed that a horse carrying a cultivator could walk between them.  The horse-hoeing idea of the system became fundamental and gave the name to his famous book, “The Horse Hoeing Husbandry,” by Jethro Tull, published in parts from 1731 to 1741.  Tull held that the soil between the rows was essentially being fallowed and that the next year the seed could be planted between the rows of the preceding year and in that way the fertility could be maintained almost indefinitely.  If this method were not followed, half of the soil could lie fallow every other year and be subjected to continuous cultivation.  Weeds consume water and fertility and, therefore, fallowing and all the culture must be perfectly clean.  To maintain fertility a rotation of crops should be practiced.  Wheat should be the main grain crop; turnips the root crop; and alfalfa a very desirable crop.