ARS | Publication request: Yield and uptake of bahiagrass under flooded environment as affected by nitrogen fertilization

Submitted to: Journal of Agricultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 12, 2012
Publication Date: August 3, 2012
Citation: Sigua, G.C., Williams, M., Chase, C.C., Albano, J.P., Kongchum, M. 2012. Yield and uptake of bahiagrass under flooded environment as affected by nitrogen fertilization. Journal of Agricultural Science. 3(4):491-500.

Interpretive Summary: Bahiagrass (Paspalum notatum Fluegge) is one of the most important forage grasses grown in these regions of the world. Establishment of complete and uniform stand of bahiagrass in a short time period is important economically. Failure to obtain a good stand of bahiagrass means loss of not only the initial investment costs, but also production and its cash value. In grasslands, waterlogging is frequently associated with other stresses, such as grazing, which may require specific and very different adaptive strategies and management. Our hypothesis in this study is that bahiagrass will be negatively affected by extended flooding and N application could offset the detrimental effect of flooding on yield, crude protein content, and nutrient uptake. The objectives of this greenhouse study conducted in 2008 and 2009 were to determine the effect of flooding duration on dry matter yield, crude protein content, and nitrogen uptake of bahiagrass and to determine if detrimental impact of flooding can be mitigated by N fertilization. Yield and uptake components of bahiagrass varied significantly with N application, but were not affected by flooding. Our results support our hypothesis that detrimental impact of flooding could be mitigated by N fertilization. Since fertilizer applications have improved the tolerance of forage grasses to waterlogging, the market value of environmental service of water storage on south Florida pastureland should be adjusted to include additional fertilizer costs. Furthermore, our results will help to increase insight into processes acting in plant communities under changing hydrological conditions could have had valuable application to many areas all over the world that were suffering from flooding. Knowledge of adaptive responses of bahiagrass to flooding and the potential off-setting effect of nitrogen fertilization could be a valuable tool in restoring damaged areas as a result of changing hydrological conditions in Florida and other Gulf states region.

Technical Abstract: Bahiagrass (Paspalum notatum Fluegge) is one of the most important forage grasses in subtropical region of USA and other tropical regions of the world. Although tolerant to short term flooding, bahiagrass is classified as a facultative upland (FACU+) species that suggest dry matter production and plant persistence might be reduced under periods of extended waterlogging. The objectives of this two-year greenhouse study (2008-2009) were to determine the effect of flooding duration on yield (DMY), crude protein content (CPC), and nitrogen uptake (NUP) of bahiagrass and to determine if nitrogen (N) fertilization could be used to mitigate flooding effects. Yield and uptake components of bahiagrass varied significantly (P=0.0001) with N application, but were not affected by flooding. Results disclosed an overwhelming effect of N application on DMY and NUP. Averaged across flooding duration, results showed that DMY (R2 = 0.91**), CPC (R2 = 0.96**), and NUP (R2 = 0.99**) were linearly related to increasing levels of N fertilization. Plants without N fertilization that were submerged between 14 to 84 days had significantly lower amount of DMY when compared with plants that were fertilized with 100 or 200 kg N ha-1. Comparable DMY and NUP were obtained between plants fertilized with 200 kg N ha-1 at 0 day of flooding (11.7±5.0 ton ha-1) and plants fertilized with 200 kg N ha-1 at 84 days of flooding (9.8±2.7 ton ha-1). These results support our hypothesis that detrimental impact of flooding could be mitigated by N fertilization.