Yield and uptake of bahiagrass under flooded environment as affected by nitrogen fertilization

Abstract

Bahiagrass ( Paspalum notatum ) 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 yield and plant persistence might be reduced under periods of extended waterlogging. The objective of this greenhouse study (2008-2009) was to determine the effect of nitrogen fertilization (0, 100, and 200 kg·N·ha –1 ) on yield (DMY), crude protein content (CPC), and nitrogen uptake (NUP) of bahiagrass under varying flooded conditions (0, 14, 28, 56, and 84 days). Results disclosed an overwhelming effect of N application on yield and uptake component of bahiagrass. Averaged across flooding duration, results showed that DMY ( R 2 = 0.91**), CPC ( R 2 = 0.96**), and NUP ( R 2 = 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 ). The practical implication of this study is that waterlogging may hamper yield and uptake while nitrogen fertilization could improve yield and uptake of bahiagrass under waterlogged condition.