By one measure at least, agriculture ranks as one of the extraordinary success stories of the past decades. Roughly one quarter of the Earth’s terrestrial surface is now under cultivation with more land converted to crop production in the 30 years after 1950 than in the previous 150. In many regions - including Europe, North America, Australia and recently Brazil, China and India – humanity has also become adept at raising yields through using inputs like fertilizers and pesticides. Yet in many poorer countries with low productivity rates and growing populations, agriculture continues to expand into marginal and fragile lands. In much of sub-Saharan Africa and large parts of Asia - according to estimates compiled by the Millennium Ecosystem Assessment (MA) – almost no highly productive land is left.