Technical Abstract: Limited availability of forage during the cool season is a common problem for livestock producers throughout the southern Great Plains. Feed shortage may be particularly acute on small farms where resource constraints limit options for increased production. There is a need to identify forage species and production practices that are sustainable and appropriate for the conditions of the resource-limited small farm. Italian ryegrass [IRG] (Lolium multiflorum Lam), tall fescue (Festuca arundinacea Schreb), tall wheatgrass (Elytrigia elongata (Host) Nevski), intermediate wheatgrass (E. intermedia (Host) Nevski) and a creeping wheatgrass (E. repens L.) x blue bunch wheatgrass (Pseudoroegneria spicata (Pursh)) hybrid were sown into clean-tilled ground or no-till over-sown into dormant unimproved warm-season pasture in small plot field experiments. Cool- and warm-season herbage dry matter (DM) yields were measured to evaluate the potential of cool-season grass species for increasing herbage production in a low-input pasture environment. Factors affecting the ability of IRG to regenerate by self-seeding were also studied. Among the perennial species tested only tall fescue sustained its production beyond two growing seasons. No-till overseeding of cool-season grasses into warm-season pasture produced greater year-round forage yields than cool-season grasses sown into cultivated ground. There was on average a 0.6 kg DM increase in year-round herbage production for each 1.0 kg DM of cool-season grass herbage produced following no-till seeding into existing warm-season pasture. On clean-tilled ground, an average of 1400 kg DM ha-1 of cool-season production was necessary to compensate for lost warm-season pasture production. IRG can be managed to produce a volunteer crop, but seed production is difficult to manipulate and the number of re-established plants is highly unpredictable. Under similar spring growing conditions an adequate stand of self-sown IRG can produce as much herbage as IRG that was no-till seeded, but self-seeding was successful in producing a crop on only 57% of occasions. Increased persistence in cool-season perennial grasses is needed if they are to be sustainable in marginal soils on small farms. Also, cultivation of existing pasture to introduce cool-season grass increases the risk of net forage yield loss on small farms.