Since time immemorial, work animals have provided humankind with essential inputs that have contributed to the development of human communities. However, with the advent of growing industrialization, work animals were prematurely replaced by machinery that, together with other industrial products, facilitated the intensification of agriculture through the development of high-yielding production systems. These systems were widely adopted in industrialized countries with strong economies. Yet high levels of production call for high levels of inputs-so high, in fact, that worldwide replication is severely limited. Other production alternatives need to be found, therefore, as rapid population growth brings a burgeoning world demand for food. These alternatives include appropriate technology applications that aim primarily to use local resources efficiently, promote integrated farm management, foster multipurpose resource use and rationally reduce the use of inputs that require high investment and heavy consumption of non-renewable energy (fossil fuels). Such semi-intensive mixed-farming patterns seek to optimize rather than maximize production levels.
