Japan
The Japanese agricultural sector accounts for about 1.4% of the total country's GDP. Only 12% of Japan's land is suitable for cultivation. Due to this lack of arable land, a system of terraces is used to farm in small areas. This results in one of the world's highest levels of crop yields per unit area, with an overall agricultural self-sufficiency rate of about 50% on fewer than cultivated.
Agriculture in Nigeria
The usage of inorganic fertilizers was promoted by Nigerian government in the 1970s.
In 1990, 82 million hectares out of Nigeria's total land area of about 91 million hectares were found to be arable. 42 percent of the cultivable area was farmed. Much of this land was farmed under the bush fallow system, whereby land is left idle for a period of time to allow natural regeneration of soil fertility. 18 million hectares were classified as permanent pasture, but had the potential to support crops. Most of the 20 million hectares covered by forests and woodlands are believed to have agricultural potential.