Old-field plant communities provide habitat components for several game species, including white-tailed deer (Odocoileus virginianus) and wild turkey (Meleagris gallopavo). Prescribed fire, herbicide application, and disking are commonly applied to improve forage and cover within old fields, but plant response on sites with nutrient-poor soils is not always favorable. Although it is reasonable to expect vegetation to respond to liming and fertilization, little information exists on how forage nutrient content and vegetation structure of old-field plants are influenced by soil amendment. We designed an experiment to test the effects of three amendment treatments (lime, fertilizer, lime + fertilizer) on four fields across Tennessee. We tested soils during spring 2017 and 2018 and applied treatment amendments based on soil test recommendations. During summer 2018, we measured vegetation structure and collected young and old forage for nutritional analysis from four commonly-occurring early successional plants: common ragweed (Ambrosia artemisiifolia), horseweed (Conyza canadensis), Canada goldenrod (Solidago canadensis), pokeweed (Phytolacca americana), and blackberry (Rubus canadensis). The effect of amendment treatment varied based on species and nutrient, but crude protein in old goldenrod leaves was the only forage/nutrient combination that soil amendment raised to meet minimum nutrition requirements of a lactating doe with twin fawns that was not already in excess of the minimum requirement for a lactating doe. Although soil amendment failed to consistently raise most nutrient values in old-fields, it did increase average vegetation height by 71% following fertilization and 65% following fertilizer + lime application. Additionally, visual obstruction from 50–100 cm, 100–150 cm, and 150–200 cm was greater following fertilizer and fertilizer + lime applications. In fields where cover is limited because of low soil productivity, amendments can be applied to increase vegetation structure for various wildlife species.