Non-food crops (such as tea, coffee, cocoa, flowers, sisal and sugarcane) take up vast tracts of land; and while they may sustain many tropical nations' economies, they also make those nations largely dependent on developed, temperate zone countries – usually the USA and the USSR – to provide their daily staples.
In many developing countries policies are biased against domestic production and in favour of imports of staple foods, which are also often themselves subsidized, or the expansion of cash crops, which means increased area devoted to their cultivation. Some food aid policies and subsidized exports by developed countries compound the biases against sound agricultural development.
More than 50% of the Caribbean's arable land is planted with crops for export; 66% in Guadeloupe; and 30% of land in East Java grows sugarcane.
The global grain supply has basically remained stagnant since 1990, while the world's population has increased by 420 million people. The problem is compounded by increasing grain-intensive meat production and consumption, particularly in Asia.
Even though there is sufficient cropland to feed the world, people in developing countries go hungry because much of their land belongs to the rich, and the rich grow luxury cash crops for export to the middle and upper classes in the developed countries. (This practice was established by colonial rule in the 17th and 18th centuries). Even if developing countries were to achieve zero population growth, their people would still go hungry unless the land was distributed to local farmers and cash export crops were replaced by local food crops.
Despite rising affluence, our likely world population of 10 billion people won't be able to live as high on the food chain as the average American. There simply won't be enough food.