Nitrogen's Effect on Native Warm Season Grass Crown Growth.

Strip mining disrupts the land surface in order to obtain subsurface substances, including coal. Vegetation, especially grasses, fill important roles in restoring the landscape of coal mine land reclamation. Red Hills Mine (RHM), located in Ackerman, MS, is a current operating large scale strip mine for lignite (coal). Current reclamation practices utilize non-native species such as browntop millet (Urochloa ramosa L.) and bermudagrass (Cynodon dactylon (L.) Pers.) due to their quick emergence and soil stabilization. The objective of this study is to evaluate yield, crown expansion (a measures of establishment) and nutritive value of native warm season grasses compared to bermudagrass. Big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium scoparium (Michx.) Nash.), indiangrass (Sorghastrum nutans (L.) Nash.), and upland switchgrass (Panicum virgatum L.) were the species included in this study. Bermudagrass and four native warm season grass test plots were established in the summers of 2015 and 2016 (2nd yr. testing). A fertilizer application (560 kg ha-1; 13-13-13) was made to all test plots in late July (2017). Harvests were performed early season, mid-season, and end of season to compare yields between the native warm season grasses and bermudagrass with and without nitrogen application. Data indicate native warm season grasses, with the exception of upland switchgrass, produced greater yields compared to bermudagrass in mid-season harvests. End of season harvests showed all species with applied nitrogen had greater yields than species without supplemental nitrogen. A species by replication interaction was present. Greater yields of native warm season grasses were found in replication 1, while yields in replication 3 were the least. Little bluestem produced the greatest yields for mid-season and end of season harvests.