Boserup revisited: Population and technology in tropical African agriculture, 1900–1940

The situations in Rwanda-Burundi and Igbo and Ibibio states of south-eastern Nigeria are compared as examples of resorting to multiple cropping and crop diversification as a technological solution to high population density. The Boserup postulation is that population growth leads to improved agricultural technology while the Allan theory is that favorable climate and soil prompts population growth overuse of the land and ultimately out-migration and urbanization. Little is known about the population and agriculture of Rwanda and Burundi until 1914 since the indigenous people excluded intruders. Their populations were estimated at 2 and 1.5 million in 1914 densities of 76 and 54/sq. km. The climate was cool with reliable rainfall the soil fertile supporting eleusine and sorghum as staples and later maize sweet potatoes and beans. Newly introduced crops were cultivated by women to fill in the previous "hungary times." As population grew yams were grown in marshes in the dry season and bananas were added then the Belgian government required all taxpayers to cultivate cassava plots. The population tripled between 1948-1978 to 249/sq. km. in Rwanda. Subsistence economy and poverty became entrenched. In Igbo and Ibibio areas of the Niger delta a similar crop diversification occurred after initial contact with Europeans from palm kernels and yams to maize plantains tomatoes and later cassava. Women cultivated the newer varieties and people exported cassava meal (gari) to the cities for convenience food. Palm oil had almost become profitable because of the invention of small presses when the world prices bottomed out. Currently soil depletion is resulting due to multiple cropping in this previously productive part of Nigeria.