ABSTRACT
From a strict standpoint the tropics include all of the area of the earth north of the Tropic of Capricorn and south of the Tropic of Cancer. The width of this belt following the equator around the earth is about 46°, more than 3000 mi or about 5000 km. Tropical plants are those that are adapted to tropical climates. Tropical crops produced in the temperate zone are principally annual vegetables or grains with relatively short lifetimes. The soils of the tropics are formed chiefly in response to high temperature and rainfall, rapid chemical action, and rapid leaching. Soil differences affect, then, the crops that can be produced. Crops were normally planted as a means of subsistence. Crops were normally planted as a means of subsistence. Multiple cropping is as common to the tropics as single cropping is to the temperate zone. Growing crops together at the same time permits complementary uses of the land, and often results in higher yields.
