 The Enga of the Western Highlands Province in New Guinea receive most of their food from growing sweet potatoes Ipomoea batatas which they plant in mulch mounds at elevations up to 2,700m or higher (Dove and Carpenter 2008).The mounds that the Enga make to plant their crops of potatoes are formed from by piling large amounts of grass taken from fallow, or unplanted, plots then by covering the grass with dirt (Wohlt 2004).The size of the mounds depends on elevation; the higher the elevation; the bigger the mounds will be.