Black polyethylene mulching involves the plants growing through holes in plastic sheets that cover the soil.

ECONOMIST: Genetic technology supports sustainable farming

"When you increase the shrub cover you trap more snow, which keeps the soil warmer, " said Sturm, calling by cellphone 70 miles east of Nome, Alaska, in a small village that serves as his base to study seasonal snow changes.

CNN: Shrub census shows Alaskan Arctic losing its cool

They will record plant species, forest structure, ash cover, soil properties, river sediment and the overall topography of the burned area.

ECONOMIST: A 30-year plan to study America��s ecology is about to begin

Farmers can also add carbon-rich compost to the soil, and plant "cover crops" such as rye or vetch during parts of the year when land otherwise would lie idle.

NPR: Iowa Farmers Look to Trap Carbon in Soil

The printers, operated by robots, would use soil from the Moon, known as regolith, to build the layered cover.

BBC: 3D printed moon building designs revealed