Abstract Stockpiled bermudagrass ( Cynodon dactylon (L.) Pers.) can potentially provide nutritious forage and extend the grazing season in the upper southeastern US Coastal Plain. This multi‐location 1‐year study evaluated the effects of four N fertilizer rates (from 0 to 135 kg ha − 1 ) and four harvest dates (from October to January) on leaf‐to‐stem ratio, herbage mass (HM), crude protein (CP), in vitro organic matter digestibility (IVOMD), nitrate‐N, N removal, and fertilizer N recovery efficiency (FNRE) of stockpiled bermudagrass. Stockpiling began in mid‐August at seven on‐farm sites encompassing seven soil series and four bermudagrass cultivars (Coastal, Midland 99, Ozark, and Tifton 44). Leaves had greater CP and IVOMD than stems. The leaf‐to‐stem ratio declined from 1.0 in October to 0.6 in January. Forage nutritive value decreased over time, with CP declining from 115 to 76 g kg −1 and IVOMD from 490 to 319 g kg −1 between October and January. Averaged across harvests, CP increased from 84 to 100 g kg −1 as N rates increased, whereas IVOMD (408 g kg − 1 ) was unaffected by N rate. The HM increased with N fertilization, ranging from 1385 to 2539 kg ha − 1 in October and from 1069 to 1670 in January. Nitrogen removal ranged from 12 to 51 kg ha − 1 and FNRE ranged from 31% to 9%, with greater values observed in October at lower N rates. Overall, late‐summer N fertilization increased HM and CP without exceeding nitrate toxicity thresholds; however, the low digestibility values indicate that energy supplementation would be required for weaned calves and dry mature cows.
Romero et al. (2026) studied this question.