Split N management and no‐till into herbicide‐desiccated warm‐season perennial grass sod favor cool‐season annual forage establishment

Abstract Mild winter temperatures in the southeastern United States allow for the implementation of cool‐season annual forage on dormant warm‐season perennial pastures of bahiagrass ( Paspalum notatum Flüggé). However, establishing cool‐season forages in low‐input systems requires overcoming the challenges of limited precipitation and inadequate plant nutrition. No‐till (NT) and split N fertilizer management strategies may mitigate these challenges by preserving soil moisture and matching N needs to plant uptake. A 2‐year study in north‐central Florida evaluated the effects of increasingly intensified tillage practices, from conventional tillage (CT) to NT, with or without chemically dormant sod, using single versus split N fertilizer management approaches on the productivity of cool‐season annual grasses with and without the presence of legumes. Nitrogen was either applied once right after planting (80‐0 lb ac −1 ) or in splits (30‐50 and 50‐30 lb ac −1 ), with a second application ∼45 days after planting, and compared with an unfertilized control. Legume establishment was limited (<1%) and did not influence the results. Conventional tillage resulted in 20% less soil moisture than the two NT treatments. Nitrogen fertilization increased tiller density by 51% and 60% relative to unfertilized forages, with no difference between split and single N applications. Average forage accumulation ranged from 0.63 to 5.51 tons dry matter ac −1 . Overall, split N management resulted in greater forage accumulation than the unfertilized control for all tillage methods, as well as than a single early N application, except under CT. Overall, NT + herbicide‐desiccated sod plus split N management enhanced cool‐season annual forage biomass.