Carbon reservoir and desertification controller
In drylands of Zimbabwe, spear grass (Heteropogon contortus) has been used to re-green desertified areas and to increase carbon sequestration, as shown in the following video (Itzkhan, 2014):
Weed
Heteropogon contortus is declared a weed in some regions of America, East Asia and in New-Caledonia (USDA, 2012; Cook et al., 2005; Gargominy et al., 1996). However, in Hawaii, there are attempts to restore native populations of spear grass, as it has been outcompeted by foreign grassland species such as buffel grass (Cenchrus ciliaris) (Cook et al., 2005).
Host for diseases
Heteropogon contortus acts as a collateral host for downy mildew on sorghum and maize (Soromessa, 2011).
Erosion control
In the USA, an improved cultivar of spear grass (Rocker) was recommended for the stabilization of critical areas, rangeland revegetation and erosion control along roadways, construction sites and other disturbed areas in the South-West desert (Pater, 1995). In India, spear grass could prevent erosion on up to 20° slopes (FAO, 2012).