Cover crop and soil reclamation
Signal grass provides a good ground cover and improves fertility as well as soil structure in banana plantations and in other environments (Vézina, 2015; Boddey et al., 1996). Its deep and dense root system prevents soil erosion, facilitates water infiltration, decreases leaching of soluble nutrients and sequesters high amounts of C in the soil (358 t/ha) (Saraiva et al., 2014; Boddey et al., 1996). It was reported to be a valuable cover crop in upland rice systems. Growing signal grass before a rice crop resulted in higher rice grain yields when ammonium sulphate and a nitrification inhibitor were applied to the crop (Rosolem et al., 2005). It was successfully used in no-tillage tomato systems to reduce weeds and improve soil structure (Silva Hirata et al., 2009).
Signal grass can be used for reclamation of lead-contaminated sites, road sides and urban areas where lead contamination is likely to have occurred. Signal grass has been found considerably more tolerant to lead than Rhodes grass (Chloris gayana), resulting in a 50% reduction of the lead (Kopittke et al., 2007).
Weed potential
Germinating seeds and leachates of green parts of signal grass had allelopathic effects on Phalaris canariensis, Lactuca sativa (standard species) and Melinis minutiflora. This may have increased its invasive potential in the Cerrados of Brazil (Barbosa et al., 2008).
Weed control
In China, signal grass is used for dense pasture cover to control the invasive and poisonous Chromolaena odorata (Wu et al., 1991 cited by Cook et al., 2005). Among treatments, digging out of Chromolaena followed by burning and planting with signal grass was the most effective (Rusdy et al., 2013). In banana agroecosystems of the French West Indies, signal grass as a cover crop is increasingly used to control weeds and to improve physical properties of the soil (Mollot et al., 2014).
Insect control
In banana plantations of the French West Indies, signal grass increased the number of Solenopsis geminata, a predator of the banana weevil (Cosmopolitus sordidus), thus contributing to controlling this pest (Mollot et al., 2012).