This is calculated from the average productivity of six overlapping sorts of area use : arable , forests , grazing land , built-up areas , carbon sequestration and fisheries .
World demand for potash has been growing steadily if not spectacularly for some years as a growing world population has made ever greater demands on the productivity of arable land . This growth is forecast to continue at some 5.5 % a year .
But the stimulus plan calls for construction on nearly three times as much arable land this year and next year as can be readily brought into cultivation elsewhere .
但是刺激方案建设用地今年就将占去近3倍的耕地,下一年可能会轻松从别处开发耕地。
With most of the world 's remaining arable land spread across the african continent , africa has a responsibility and an opportunity to maximize agricultural promise and provide food for your own people and the world as well .
In the western highlands and islands much of the land is poor and rocky , with cultivation only possible in glens and coastal areas , while most arable land lies along the north-eastern coastal plain and in the lowlands .
Madagascar may be a surprising example as it witnessed what is perhaps the most notorious land grab of all : a south korean company was offered half the country 's arable land-a proposal that fuelled protests which eventually toppled the government who approved the deal .
Collieries destroy arable land and grazing pastures , erode topsoil , worsen air and water pollution , increase levels of river sediment ( raising the risk of floods ) , and accelerate deforestation ( especially if the coal was used to make charcoal ) .
A team of scientists at rothamsted , the uk 's largest agricultural research centre , suggests that extra carbon dioxide in the air from global warming , along with better fertilisers and chemicals to protect arable crops , could hugely increase yields and reduce water consumption .