The area currently under cultivation is 1.5 billion hectares, so if all that extra land could be used it would represent an increase of one-third.
目前耕种中的面积为1.5亿公顷，因此如果剩下的土地也用于耕种，就有三分之一的增长。
2
Moreover, simply expanding the areaof the earth's surface that is under cultivation is likely to cause deforestation, which is environmentally harmful.
此外，单纯地扩张地球表面的耕地面积会带来森林退化，这对环境有着严重危害。
3
Using traditional techniques such as crop rotation, compost and manure to supply the soil with nitrogen and other minerals would have required a tripling of the area under cultivation.