Building an agro-ecosystem

An average 2,000-3,000 litres per day is needed to produce food per person, compared to 200-300 litres for household use per day.

“Given that we have to produce more food, how do we do that and not destroy ecosystems? That’s the biggest question in agriculture right now – not producing more food but doing it sustainably,” said David Molden, research director of the Sri Lanka-based International Water Management Institute. His institute released a new report on building “agro-ecosystems” to protect water and food security. The report asserts that “it is possible to feed everyone without massive and irreversible damage to our ecosystems – damage that would ultimately endanger both water and food security in the future.” Making it happen, however, is a huge challenge, the report acknowledges.

Researchers and people confronting water shortages around the world are coming up with some creative ways to produce more food with less water. Those include everything from raising fish in rice paddies to planting trees on farmland to protect and enrich soils, Molden said. “The best people to figure it out are local people. It’s their survival. It’s amazing what kinds of things they come up with,” he added.

In Africa, where degraded soils are a widespread problem, some farmers are switching from plowing fields to “minimum tillage” systems that protect the structure of the soil, allowing it to absorb and hold more water. Such changes can help get farmers through short drought periods that could otherwise damage their crops, the researcher said. Under traditional plowing and planting systems, only about 20 percent of rainfall is absorbed into crops, with the rest lost to evaporation and runoff. Improving soils – through planting fertilizer trees, adding compost and avoiding tilling fields, for instance – can help crops absorb up to 70 percent of the rain that falls, Molden said. That is particularly crucial as climate change increases the variability of rainfall and snowmelt, making the water available to farmers less reliable, he said. “When you’re sitting on the brink of water scarcity, a five to 10 percent difference (in water availability) is huge,” Molden added.

Agricultural experts increasingly understand that simply clearing land for agricultural expansion – including cutting trees and draining wetlands – is not the best way to boost production in the long run because of the impacts it can have on water availability, Molden said. By integrating trees and hedgerows, farmers can prevent runoff and soil erosion and preserve more water for feeding their crops.

“It’s possible to feed everybody and still come up with a good healthy environment,” Molden said. “But that’s not the track we’re on."