ABSTRACT
Historically, as populations have grown and agricultural producers have devised new ways of using resources to provide food and income, relationships between inputs and outputs have changed. This process goes under the general term intensification. This chapter explores how this process works in practice. The English agricultural revolution of the 18th century is a case in point. Livestock occupied a central place in the English farming system, as is the case with African low-resource agriculture. The first system illustrated is the mixed farming system of the Serer people of the southern part of the so-called "groundnut basin" of Senegal, which has an average population density on the order of 75 persons per square kilometer. This is in the semi-arid tropics zone. The Serer crop rotation pattern uses space to great advantage to maximize land and labor use during the relatively brief single rainy season when all crop cultivation must be performed.
