■ Average crop yields increased by 20% between 1985 and 2005, “substantially less than the often-cited 47% production increase for selected crop groups”;
■ Globally, only 62% of crop production by mass is for human food; 35% is for animal feed and 3% for biofuels.
■ The land devoted to raising animals – including pasture, grazing and animal feed production – is an “astonishing” three-quarters of the total, and “the amount of land (and other resources) devoted to animal-based agriculture merits critical evaluation”.
■ Most agricultural expansion is in the tropics, where “about 80% of new croplands are replacing forests”. “Slowing (and ultimately, ceasing) the expansion”, particularly in the tropics, is “an important first step” to sustainability.
■ Irrigation accounts for 70% of global freshwater withdrawals, which is “of particular concern”.
■ Fertiliser use, manure application and leguminous crops (which fix nitrogen in the soil) have “dramatically disrupted” the global nitrogen and phosphorus cycles.