Something quite remarkable happened during the past century, and especially since 1950. Yields rose dramatically in the basic cereal crops such as wheat, rice, and maize, and in other crops as well. Casual inquiry to an agricultural expert about the source of the increase is likely to bring a response such as, “Well, farmers now use better plant varieties and more fertilizer than they used to, so the yields went up.” At the simplest level, this response is perfectly adequate and true. Better varieties and more fertilizer have made it possible to get larger harvests from the same plot of ground. Unfortunately, the simple answer immediately provokes yet further questions: How did farmers obtain the new and better plant varieties? Why did they use more fertilizer? When did farmers start changing their practices? Where? Why? Who helped them? The last question quickly leads the inquiry into the realm of agricultural science, because scientists enabled farmers to change their practices. Especially important were plant breeders and soil fertility experts. Thus a new realm of questions is opened: How did scientists discover the methods for higher yields? When did they do their research? Where? Why? Who paid for the research? Why? What is the significance of this scientific change? These questions seem simple, but agriculture is a tricky topic to address. It generates an inordinate number of paradoxes, puzzles, and ironies, which makes answering the queries difficult. Consider, for example, just a few: . . . Agriculture was once the place where the vast majority of human beings worked and lived, but now it increasingly provides a place for only a small minority of people. Agriculture’s harvests are the only source from which most people obtain enough food to stay alive, but few nonfarmers understand or care about its workings. Agriculture is often considered to be a landscape that is alive, verdant, lush, and redolent of wholesome naturalness, but in reality it represents the complete destruction, indeed obliteration, of natural ecosystems and wildlife habitat. . . .
