An article in The Economist describes the history of wheat. It’s a marvelously written piece worth reading in its entirety, but I have quoted below a just few paragraphs that I think make some good points about modern farming, genetic modification and the need for high yields. All bold is mine.
The article starts with a brief description of what “wheat” really is - an artificial mutant incapable of living uncultivated in the wild:
Strange is the word, for wheat is a genetic monster. A typical wheat variety is hexaploid—it has six copies of each gene, where most creatures have two. Its 21 chromosomes contain a massive 16 billion base pairs of DNA, 40 times as much as rice, six times as much as maize and five times as much as people. It is derived from three wild ancestral species in two separate mergers. The first took place in the Levant 10,000 years ago, the second near the Caspian Sea 2,000 years later. The result was a plant with extra-large seeds incapable of dispersal in the wild, dependent entirely on people to sow them.
Like many artificial crops, wheat would not survive in the wild, a point that should be remembered when calculating the risks of genetic engineering and “superweeds”.
The article describes the history of farming from its start roughly 9,000 years ago. First the ancient farmers used manure from their cattle to fertilize their fields, but when this became insufficient and nutrients were depleted, the voices of doom predicted mass starvation. Mechanization in the form of sowing and threshing machines were introduced. These were initially opposed but later accepted as being normal and necessary. Later on, tractors helped increase yields still further. But it was artificial fertilizer that replaced manure (and the animals needed to produce it), that eventually allowed enough crops to be grown. However, it was Norman Borlaug and his dwarf wheat that really made the difference:
India was on the brink of mass famine. Huge shipments of food aid from America were all that stood between its swelling population and a terrible fate.
Borlaug refused to be so pessimistic. He arrived in India in March 1963 and began testing three new varieties of Mexican wheat. The yields were four or five times better than Indian varieties. In 1965, after overcoming much bureaucratic opposition, Swaminathan persuaded his government to order 18,000 tonnes of Borlaug's seed.
Eager farmers took it up with astonishing results. By 1974, India wheat production had tripled and India was self-sufficient in food; it has never faced a famine since. In 1970 Norman Borlaug was awarded the Nobel Peace Prize for firing the first shot in what came to be called the “green revolution”.
Other breeds followed. The interesting thing is how they were produced:
Today scientists use thermal neutrons, X-rays, or ethyl methane sulphonate, a harsh carcinogenic chemical—anything that will damage DNA—to generate mutant cereals. Virtually every variety of wheat and barley you see growing in the field was produced by this kind of “mutation breeding”. No safety tests are done; nobody protests. The irony is that genetic modification (GM) was invented in 1983 as a gentler, safer, more rational and more predictable alternative to mutation breeding—an organic technology, in fact. Instead of random mutations, scientists could now add the traits they wanted.
In 2004 200m acres of GM crops were grown worldwide with good effects on yield (up), pesticide use (down), biodiversity (up) and cost (down). There has not been a single human health problem. Yet, far from being welcomed as a greener green revolution, genetic modification soon ran into fierce opposition from the environmental movement.
Compare the earlier methods for producing hybrids with the more surgical genetic engineering methods that allow just specific genes to be altered. Also compare the current opposition to genetic modification, to the earlier opposition to the plough, the threshing machine and the tractor; also consider the opposition to Borlaug’s dwarf wheat.
The article goes on to describe how the world population appears to be about to plateau. The key difference is in developing countries where the number of children born per woman has fallen from six to three.
Human beings may be the only creatures that have fewer babies when they are better fed. The fastest-growing populations in the world over the next 50 years will be those of Burkina Faso, Mali, Niger, Somalia, Uganda and Yemen. All except in Yemen are in Africa. All are hungry. All remain untouched by Borlaug's green Revolution: all depend on primarily organic agriculture.
We can speculate on the reasons for this. Better education and equal rights for women (and birth control) are likely to be a part of it. But it seems likely that the reduction in subsistence farming, where families have to grow their own food to live, has reduced the need for couples to have large families to tend their land for them. Ironically, poverty seems to encourage large families; in rich countries, people want fewer children.
The article ends on the need to grow even more food for the estimated ten billion people still expected by 2050, and what this implies for farming:
That will mean either better yields or less rainforest—which is why fertilisers, pesticides and transgenes are the best possible protectors of the planet.
As I have said before, a challenge will be to feed those extra people, but a bigger challenge will be to feed them without chopping down more forest, and without losing more waste-land to cultivation.