Forage and Nitrogen Contributions of Arrowleaf and Subterranean Clovers Overseeded on Bermudagrass and Bahiagrass 1

Tropical perennial grasses are the foundation of the pasture systems in the southeastern USA. However, they are low quality and require N fertilizer. Forage production and distribution and N accumulation of clover‐grass mixtures were compared to that of the grass alone receiving various rates of N fertilizer on a Crowley soil (fine, mortmorillonitic, thermic Typic Albaqualf). ‘Coastal’ bermudagrass [ Cynodon dactylon (L.) Pers.] and ‘Pensacola’ bahiagrass ( Paspalum notutum Flugge) sods were (i) overseeded with ‘Yuchi’ arrowleaf ( Trifolium vesiculosum Savi) or ‘Mt. Barker’ subterranean clovers ( Trifolium subterraneum L.), (ii) fertilized with 0, 84, 168, 252, or 336 kg N ha −1 , or (iii) overseeded with arrowleaf or subterranean clover plus 112 kg N ha −1 . Dry matter production of clover‐Coastal bermudagrass and clover‐bahiagrass mixtures was not significantly different from the grass alone at the 168 and the 252 kg N ha −1 rate, respectively. Overseeding clovers improved seasonal forage distribution by providing forage one to two months earlier and reduced the May–June forage peak exhibited by the N fertilizer‐grass treatment. Average annual N accumulations of clover‐grass mixtures ranged from 177 to 217 kg N ha −1 , which equaled or exceeded the 336 kg N rate except for the arrowleaf–bermudagrass mixture. The amount of N fertilizer required by the grass to replace the clover dry matter contribution was 127, 211, 160, and 254 kg N ha −1 for the arrowleaf‐bermudagrass, arrowleaf‐bahiagrass, subterranean‐bermudagrass, and subterranean‐bahiagrass mixtures, respectively. Applying 112 kg N ha −1 to clover‐grass mixtures did not improve total yield, forage distribution, or N accumulation, but did decrease percentage clover in the stand 5 to 33%.