However, by 2050 we will have 9 billion mouths to feed, 3 billion more than today.
‘Agriculture must become the solution to environmental problems in 50 years. If we don't have systems that make the environment better—not just hold the fort—then we're in trouble,’ says Kenneth Cassman.
Advocates of organic farming like to point out that fields organically managed can produce yields just as high as fields enhanced with synthetic fertilisers. For example, Bill Liebhardt, at the Rodale Institute in Pennsylvania, recently compiled the results of such comparisons for corn, wheat, soybeans and tomatoes in the US and found that the organic fields averaged between 94 and 100 percent of the yields of nearby conventional crops.
Vacay Smil, of the University of Manitoba in Winnipeg, estimates that if farmers worldwide gave up the 80 million tonnes of synthetic fertiliser they now use each year, total grain production would fall by at least half. Either farms would have to double the amount of land they cultivate—at catastrophic cost to natural habitats—or billions of people would starve.
Technologically advanced farmers can now monitor their yields and target their fertiliser to the parts of the field where it will do the most good, which, in turn, increases the yield. Eventually, farmers may incorporate long-term weather forecasts into their planning so they can cut back on fertiliser use when the weather is likely to make harvests poor anyway, says Ron Olson, an agronomist from Florida.
Questions
1. Without the use of synthetic fertilisers, large numbers of people would die of hunger.
2. We need agricultural methods that work for the environment.
3. In future, the quantity of fertiliser used will be linked to predicted harvests.
4. The output from organic soils is very nearly equal to that from fields treated with chemical fertilisers.