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 f...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 (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). 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.展开更多
Background：Previous research indicates that bahiagrass may be successfully conserved as baleage,but nutritive value is typically low for lactating dairy cows.The purpose of this study was to determine the effect of a...Background：Previous research indicates that bahiagrass may be successfully conserved as baleage,but nutritive value is typically low for lactating dairy cows.The purpose of this study was to determine the effect of adding modest amounts of alfalfa forage（22%）,achieved by inter-seeding alfalfa into an existing bahiagrass pasture,on baleage nutritive value and lactation performance of Holstein cows.Forage treatments employed were monoculture bahiagrass baleage（MBB;negative control）,bahiagrass-alfalfa mixture baleage（BAB） and conventional corn silage（CCS;positive control）.Thirty six mid lactation Holstein cows[34.8 ±5.8 kg 3.5%fat-corrected milk and 112 ± 19 d in milk（DIM）]were stratified according to milk yield and DIM and assigned randomly to 1 of 3 forage treatments.Cows were trained to Calan feeding gates and were offered a common CCS-based TMR in a 10-d covariance period followed by a 42-d treatment feeding period.Results：The BAB contained more protein and less NDF than MBB（12.6 vs 10.3%CP and 71.8 vs 76.6%NDF）.Diet DMI was similar for MBB and BAB（19.5 vs 21.6 kg/hd/d）,but cows consumed more of the CCS diet（25.5 kg/hd/d）than either baleage-based diet.Cows offered BAB tended to produce more milk than cows offered MBB based TMR（28.4 vs 26.1 kg/hd/d）,but both baleage diets generated less milk than CCS-based diets（33.1 kg/hd/d）.Milk cumpusition was similar across diets except for milk protein concentrations which were higher tor CCS than either MBB or BAB diets;however,milk urea nitrogen（MUN） was lowest for cows fed CCS diets.Cow BW gain was higher for BAB than MBB implying that a portion of the higher energy contributed by the alfalfa was being used to replenish weight on these mid lactation cows.Conclusions：Data from this study indicate that alfalfa inter-seeded in bahiagrass sod that produces BAB with as little as 22%alfalfa may improve nutritive value compared to monoculture bahiagrass baleage and marginally improve lactation performance of Holstein cows.However,the CCS diet was vastly superior to either MBB or BAB-based diets for milk production.展开更多
文摘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 (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). 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.
文摘Background：Previous research indicates that bahiagrass may be successfully conserved as baleage,but nutritive value is typically low for lactating dairy cows.The purpose of this study was to determine the effect of adding modest amounts of alfalfa forage（22%）,achieved by inter-seeding alfalfa into an existing bahiagrass pasture,on baleage nutritive value and lactation performance of Holstein cows.Forage treatments employed were monoculture bahiagrass baleage（MBB;negative control）,bahiagrass-alfalfa mixture baleage（BAB） and conventional corn silage（CCS;positive control）.Thirty six mid lactation Holstein cows[34.8 ±5.8 kg 3.5%fat-corrected milk and 112 ± 19 d in milk（DIM）]were stratified according to milk yield and DIM and assigned randomly to 1 of 3 forage treatments.Cows were trained to Calan feeding gates and were offered a common CCS-based TMR in a 10-d covariance period followed by a 42-d treatment feeding period.Results：The BAB contained more protein and less NDF than MBB（12.6 vs 10.3%CP and 71.8 vs 76.6%NDF）.Diet DMI was similar for MBB and BAB（19.5 vs 21.6 kg/hd/d）,but cows consumed more of the CCS diet（25.5 kg/hd/d）than either baleage-based diet.Cows offered BAB tended to produce more milk than cows offered MBB based TMR（28.4 vs 26.1 kg/hd/d）,but both baleage diets generated less milk than CCS-based diets（33.1 kg/hd/d）.Milk cumpusition was similar across diets except for milk protein concentrations which were higher tor CCS than either MBB or BAB diets;however,milk urea nitrogen（MUN） was lowest for cows fed CCS diets.Cow BW gain was higher for BAB than MBB implying that a portion of the higher energy contributed by the alfalfa was being used to replenish weight on these mid lactation cows.Conclusions：Data from this study indicate that alfalfa inter-seeded in bahiagrass sod that produces BAB with as little as 22%alfalfa may improve nutritive value compared to monoculture bahiagrass baleage and marginally improve lactation performance of Holstein cows.However,the CCS diet was vastly superior to either MBB or BAB-based diets for milk production.
