The Faidherbia fixes nitrogen in the soil, protects fields from wind and water erosion and contributes organic matter to soils when its leaves drop.
More than 60% of farmland in Britain is managed under environmental schemes to protect field margins, streams and ditches, he says.
As a state legislator, the Republican teamed up with a prominent Democrat to introduce a bill to protect field workers, many of them illegal immigrants.
The preferred dye was the precious indigo, a plant found in different parts of Japan, because it was thought to have magical properties and protected field workers from mosquitoes and snakes.
Calderon recounted a 2004 meeting in a sun-baked field in Shafter with farm workers and others trying to build support for Chu's proposed legislation to protect field hands from sometimes-fatal sunstroke.
Ditch networks were traditionally designed to protect fields from soil erosion or control waterlogging.
"You can't put doors up to protect fields," said Maj. Jesús Gayoso, an analyst for the Guardia Civil, Spain's military police.
Here, farmers and politicians have considered the corps' flood-control projects as an indispensable line of defense to protect fields and towns.
In Sudan, the Forests National Corporation started reserving areas in the 1980s, and a decade later the Sudan National Adaptation Programme of Action started planting belts of trees to protect fields and homes.
The agency has not said what they will include, but they are expected to deal with basics like hand-washing stations for field workers, tests of irrigation water and measures to protect fields from wild animals that can track in bacteria.
