Theme 1: Grassland Ecology
Description
Aeschynomene (Aeschynomene americana L.) is a warm-season annual legume commonly overseeded into warm-season perennial grass pastures in tropical and subtropical regions. Although aeschynomene usually increases forage production and nutritive value, there is limited information about the ecosystem services provided by this legume. The objective of these studies was to evaluate the effects of overseeding aeschynomene into bahiagrass (Paspalum notatum Flüggé) pastures on nutrient dynamics and microbial N-cycling gene abundances. The studies were conducted in Ona, FL, from April to March 2019-2020 and 2020-2021. Treatments were the split-plot arrangement of two forage systems treatments (overseeding aeschynomene into bahiagrass or bahiagrass monoculture; main plots) and two N fertilization levels [0 (control) and 60 kg N ha-1 ; sub-plot], distributed in a randomized complete block design with four replicates. Forage characteristics were evaluated 8-wk after seeding and every 35 d thereafter. The static chamber technique was used to estimate nitrous oxide (N2O) emissions. The litter bag technique was used to estimate organic matter (OM) and N decomposition. Nitrogen-cycling gene abundances were measured by qPCR. Bahiagrass-aeschynomene had greater crude protein concentration than bahiagrass monoculture but there was no difference in forage accumulation. Nitrogen fertilization increased forage accumulation and daily N2O emissions. Litter from bahiagrass-aeschynomene had greater OM and N decomposition rates than bahiagrass only, and N fertilization did not affect litter decomposition. There were no differences in N-cycling microbial gene abundances among treatments. Overseeding aeschynomene into bahiagrass may provide additional ecosystem services, but the magnitude is conditional to the establishment and proportion of aeschynomene in the pasture botanical composition.
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Ecosystem Services Provided by Overseeding Aeschynomene Into Bahiagrass Pastures in South Florida
Aeschynomene (Aeschynomene americana L.) is a warm-season annual legume commonly overseeded into warm-season perennial grass pastures in tropical and subtropical regions. Although aeschynomene usually increases forage production and nutritive value, there is limited information about the ecosystem services provided by this legume. The objective of these studies was to evaluate the effects of overseeding aeschynomene into bahiagrass (Paspalum notatum Flüggé) pastures on nutrient dynamics and microbial N-cycling gene abundances. The studies were conducted in Ona, FL, from April to March 2019-2020 and 2020-2021. Treatments were the split-plot arrangement of two forage systems treatments (overseeding aeschynomene into bahiagrass or bahiagrass monoculture; main plots) and two N fertilization levels [0 (control) and 60 kg N ha-1 ; sub-plot], distributed in a randomized complete block design with four replicates. Forage characteristics were evaluated 8-wk after seeding and every 35 d thereafter. The static chamber technique was used to estimate nitrous oxide (N2O) emissions. The litter bag technique was used to estimate organic matter (OM) and N decomposition. Nitrogen-cycling gene abundances were measured by qPCR. Bahiagrass-aeschynomene had greater crude protein concentration than bahiagrass monoculture but there was no difference in forage accumulation. Nitrogen fertilization increased forage accumulation and daily N2O emissions. Litter from bahiagrass-aeschynomene had greater OM and N decomposition rates than bahiagrass only, and N fertilization did not affect litter decomposition. There were no differences in N-cycling microbial gene abundances among treatments. Overseeding aeschynomene into bahiagrass may provide additional ecosystem services, but the magnitude is conditional to the establishment and proportion of aeschynomene in the pasture botanical composition.
