The Wealth of Nations by Part 1 Chapter 11 Page 231

The same causes, therefore, the want of manure, and the disproportion between the stock employed in cultivation, and the land which it is destined to cultivate, are likely to introduce there a system of husbandry not unlike that which still continues to take place in so many parts of Scotland. Mr. Kalm, the Swedish traveller, when he gives an account of the husbandry of some of the English colonies in North America, as he found it in 1749, observes, accordingly, that he can with difficulty discover there the character of the English nation, so well skilled in all the different branches of agriculture. They make scarce any manure for their corn fields, he says; but when one piece of ground has been exhausted by continual cropping, they clear and cultivate another piece of fresh land; and when that is exhausted, proceed to the third.