Marx’s research for Capital included careful study of Justus von Liebig’s work on agricultural chemistry, which he described as “more important for this matter than all the economists put together.”

It hardly needs to be added that these new conditions also established the foundation for new and more effective forms of colonial expansion and imperialism, as well as new needs for such expansion, in search of new markets and resources.

This pattern signifies more than is apparent at first glance. It testifies, among other things, to the transformation of social property relations in the heartland of agrarian capitalism, the south and southeast, and the dispossession of small producers, a displaced and migrant population whose destination would typically be London. The growth of London also represents the growing unification not only of the English state but of a national market. That huge city was the hub of English commerce—not only as a major transit point for national and international trade but as a huge consumer of English products, not least its agricultural produce. The growth of London, in other words, in all kinds of ways stands for England’s emerging capitalism, its integrated market—increasingly, a single, unified, and competitive market; its productive agriculture; and its dispossessed population.

And market dependence was a cause, not a result, of mass proletarianization.

Unimproved land, land not rendered productive and profitable (such as the lands of indigenous peoples in the Americas), is “waste,” and it is the right, even the duty, of improvers to appropriate it.

the productive and profitable utilization of property, its improvement.

New conceptions of property were also being theorized more systematically, most famously in John Locke’s Second Treatise of Government. Chapter 5 of that work is the classic statement of a theory of property based on the principles of improvement.

It meant, even more fundamentally, new forms and conceptions of property. “Improved” farming, for the enterprising landlord and his prosperous capitalist tenant, ideally required enlarged and concentrated landholdings. It also—and perhaps even more—demanded the elimination of old customs and practices that interfered with the most productive use of land.

Improvement was also a major preoccupation of the Royal Society, which brought together some of England’s most prominent scientists (Isaac Newton and Robert Boyle were both members of the Society) with some of the more forward-looking members of England’s ruling classes—like the philosopher John Locke and his mentor, the first Earl of Shaftesbury, both of whom were keenly interested in agricultural improvement.

so that, for example, some radical thinkers in the nineteenth century might embrace “improvement” in the sense of scientific farming, without its connotation of commercial profit

The word “improve” itself, in its original meaning, did not mean just “making better” in a general sense but literally (based on the old French for “into,” en, and “profit,” pros, or its oblique case, preu) doing something for monetary profit, and especially cultivating land for profit. By the seventeenth century, the word “improver” was firmly fixed in the language to refer to someone who rendered land productive and profitable, especially by enclosing or reclaiming waste. Agricultural “improvement” was by then a well established practice, and in the eighteenth century, in the golden age of agrarian capitalism, “improvement,” in word and deed, came truly into its own.

The result was an agrarian sector more productive than any other in history. Landlords and tenants alike became preoccupied with what they called “improvement,” the enhancement of the land’s productivity for profit.

This pattern would be reproduced in the colonies, and indeed in post-Independence America, where the independent small farmers who were supposed to be the backbone of a free republic faced, from the beginning, the stark choice of agrarian capitalism: at best, intense self-exploitation, and at worst, dispossession and displacement by larger, more productive enterprises.

To meet economic rents in a situation where other potential tenants were competing for the same leases, tenants were compelled to produce cost-effectively, on penalty of dispossession.

The effect of the system of property relations was that many agricultural producers (including prosperous “yeomen”) were market-dependent, not just in the sense that they were obliged to sell produce on the market but in the more fundamental sense that their access to land itself, to the means of production, was mediated by the market.

Landlords had a strong incentive, then, to encourage—and, wherever possible, to compel—their tenants to find ways of increasing their output. In this respect, they were fundamentally different from rentier aristocrats who throughout history have depended for their wealth on squeezing surpluses out of peasants by means of simple coercion, enhancing their powers of surplus extraction not by increasing the productivity of the direct producers but rather by improving their own coercive powers—military, judicial, and political.