But surely we can grow more food on each acre, can't we? Forty
years ago, the world's average wheat yield was half a ton per
acre. Now it is 1.2 tons per acre. French farmers average 3.2.
The highest recorded yield on a single farm is 6.4. Those
staggering increases sound promising until you study the numbers
behind the numbers. Globally, the tripling of grain production
over the past 50 years was accompanied by a 20-fold increase in
nitrogen fertilizer use. The last doubling of U.S. food output
was accomplished with a sixfold increase in fertilizer use and
an even greater rise in pesticide applications. The price of
high yields, it turns out, is the use of synthetic chemicals
that bring with them devastating environmental effects. Wherever
soluble synthetic fertilizers are used heavily, there is water
pollution. Fertilizers don't stay on fields or go only into
crops. They run off into streams and leach into groundwater.
Nitrate from fertilizer is one of the most common contaminants
in drinking water. In U.S.