Improving Yield and Protein Content of Forages Under Flooded Condition.

Flooding can have catastrophic impacts on the productivity of arable farmland, grassland pastures, as most crops including forages are intolerant to excess water. The objectives of this study were to determine the effect of flooding duration and N fertilization on dry matter yield (DMY) and crude protein content (CPC) of three Florida forage species [i.e., bahiagrass  (Paspalum notatum), limpograss (Hemarthria altissima), and maidencane (Panicum hemitomon)].  Bahiagrass and limporass are introduced species that are widely used in the Kissimmee River basin, while maidencane is native species adapted to the same moisture regime as limpograss. Results disclosed that DMY and CPC varied significantly with flooding durations (P≤0.001) and levels of N fertilization (P≤0.001). Averaged across flooding duration and levels of N, limpograss had the greatest DMY of 11.6 ton ha^-1 followed by maidencane (8.6 ton ha^-1) and bahiagrass (8.5 ton ha^-1) while bahiagrass had the highest CPC of 6.9% followed by maidencane (6.0%) and limpograss (3.7%). The overall yield response of the three forage species: bahiagrass (R²=0.95**); limpograss (R²=0.93**); and maidencane (R²=0.99**) were linearly related to increasing levels of N fertilization. Crude protein contents of three forage species: bahiagrass (R²=0.97**); limpograss (R²=0.99**); and maidencane (R²=0.87**) were also linearly related to increasing levels of N fertilization. Averaged across forage species, DMY of forages fertilized with 200 kg N ha^-1 with no flooding were statistically comparable with plants that were fertilized with 200 kg N ha^-1and flooded for 84 days. Our results support our hypothesis that detrimental impact of flooding could be mitigated by N fertilization. Results will have significant impact in developing proper management of forage production in flood-prone pasture areas.