Outgrowing the Earth Part 6
OUTGROWING THE EARTH THE FOOD SECURITY CHALLENGE IN AN AGE OF FALLING WATER TABLES AND RISING TEMPERATURES LESTER BROWN EARTHSCAN 2005 PART VI Chapter 4: Raising the earth’s Productivity During the last half of the 20th century the world’s farmers more than doubled the productivity of their land, raising grain yield per hectare from 1.1 …