In the last half century, Earth's population has increased two-fold while land used to produce food, livestock feed, and fiber crops rose by only 13%. This considerable achievement has been called a green revolution made possible by a powerful combination of new technologies, including genetic improvement of major staple food crops, development and widespread use of mineral fertilizers and pesticides, and expansion of irrigated area. The result is that a few high-yield cropping systems now provide the major portion of human food from a relatively small area of arable land (Chapter 1.2). While these developments have had remarkable success in raising productivity and sparing natural ecosystems from conversion to agriculture, there are nonetheless growing concerns about negative environmental impacts. Here we learn how rapid technological advancement enabled conversion to high-yield systems and consider future challenges to sustaining them and their high productivity.

Common features of high-yield systems

High-yield cropping systems have evolved through intensification of traditional systems during the past 50 years. This process involved: (i) producing more crops per year per unit land area, i.e., temporal intensification; and (ii) more intensive use of inputs (fertilizers, manure, irrigation, pesticides) to alleviate yield-limiting abiotic and biotic stresses, i.e., input intensification. High-yield systems are not only found in developed countries where large-scale, mechanized agriculture predominates, but also in developing countries where small-scale, labor-intensive systems remain the norm. Examples of the latter include continuous rice, rice–wheat, and cotton and sugarcane systems in developing countries of south, southeast, and east Asia.