Thursday 5 April 2012

The world needs new ways to grow food carries a great blog entry on something which fascinates me - perennial crops.

Author Peter C. Kahn, a professor of biochemistry at Rutgers University in New Jersey, USA, argues that "unless we rethink the way we grow our food and use our resources, more and more people will go hungry. For half a century, he says, we’ve concentrated on growing annual crops such as wheat, corn and rice — crops that have to be planted and harvested every year, wearing out the land and using vast amounts of water for irrigation. This is not sustainable."

He continues by saying "that we can reverse the trend by reinvesting in agriculture, especially in perennial crops — plants that don’t have to be replanted every year. Perennials can produce food and fuel, and their cultivation is less damaging to land and water. Perennials include food and fuel-producing trees, grasses and — at least potentially — perennial variations of many crops now cultivated annually."

The article says that "farmers, governments and corporations [have] miss[ed] the advantages of perennials almost entirely. At current yields, for example, a mere 2.5 acres of walnuts could supply a nutritious 10 percent of a 2,000-calorie diet to 47,000 people. We want to redress that imbalance, not by replacing annual crops, but by using perennials to reclaim hundreds of millions of acres of damaged land all over the Earth."

"Our overdependence on annual crops has caused land to lose productivity through deforestation, development, overgrazing and poor agricultural practices. Annual single-crop cultivation forces us to pump water out of our aquifers faster than nature can refill them, dropping water tables and leading us to hunt for water in “fossil aquifers,” laid down millions of years ago. Those aquifers are not rechargeable. When they go dry, agriculture dependent on them ceases. The 16 percent of the world’s crop land that is irrigated produces 36 percent of the global harvest."

"Perennials would increase soil organic matter, reduce pollution, stabilize soils against erosion and would help fields, forests and rangelands retain water, reducing flooding and helping aquifers to recharge. The approach also would harvest large quantities of carbon dioxide, thereby helping to ameliorate global climate change."

Read the full post on here.