In the 1830s, The Farmers’ Cabinet, and American Herd-book arrived in the mailboxes of about 10,000 farmers in United States. It covered nearly all aspects of production agriculture, from growing crops and livestock to processing, financing and selling them. Twice each month, farmers received 16 book-pages for the modern equivalent price of about US$48 annually.
Rotations were a regular focus.
“We may draw the following conclusions: 1st. That however well prepared a soil may be, it cannot nourish a long succession of crops without becoming exhausted.
“2d. Each harvest impoverishes the soil to a certain extent, depending upon the degrees of nourishment which it restores to the earth.
“3d. The cultivation of spindle roots ought to succeed that of running and superficial roots.
“4th. It is necessary to avoid returning too soon to the cultivation of the same, or analogous kinds of crops, in the same soil.
“5th. It is very unwise to allow two kinds of plants, which admit of the too ready growth of weeds among them, to be raised in succession.
“6th. Those plants that derive their principal support from the soil should not be sown, excepting when the soil is sufficiently provided with manure.
“7th. When the soil exhibits symptoms of exhaustion from successive harvests, the cultivation of those plants that restore most to the soil, must be resorted to.
“These principles are confirmed by experience; they form the basis of a system of agriculture, rich in its products, but more rich in its economy, by the diminution of the usual quantity of labor and manure.”
But rotations should be tempered by the economy:
“Though his lands may be suited to cultivation of a particular kind, his interests may not allow him to enter upon it. The more abundant any article is, the lower will be its price; he ought then to prefer those crops of which the sale is most secure. If a product cannot be consumed upon the spot, it is necessary to calculate the expense of transporting it to a place of sale in countries where it is needed. An intelligent farmer, whose lands lie at a distance from a market, will endeavor to avoid the expenses incident to the transportation of his products.”
I am thinking China might be an issue for the 2019-20 rotation plan.