Grazing Termination Dates of Summer-Dormant Flecha Tall Fescue

Summer-dormant, Mediterranean-type tall fescue (Festuca arundiancea Schreb.) has potential to replace summer-active, Continental-type tall fescue and trad-itional, annual small grain graze-out systems in the Southern Great Plains region of the USA. This region is characterized by severe water deficits accompanied by extreme heat in summer, and by relatively mild, rainy winters (Malinowski et al. 2009). Although the climate of the southern Great Plains is different from the Mediterranean climate, the temperature and precipitation patterns during summer are historically similar. However, in the past decade, the bimodal precipitation pattern with peaks in May and September has become highly unpredictable, resulting in delayed planting of small grains in autumn and lack of winter forage for grazing livestock (Malinowski et al. 2009). As a perennial forage crop, summer-dormant tall fescue provides a source of forage during the winter months when warm-season grasses are dormant, reducing pasture establishment costs, soil erosion, and the time and labor associated with annual forage systems (Kindiger and Conley 2002; Beck et al. 2008; Islam et al. 2011). Replacing summer-active with summer-dormant cool-season grasses can provide some resilience in the forage systems to extreme seasonal precipitation and temperature patterns (Clark and Harris 2009; Malinowski et al. 2005). These conditions, combined with relatively mild winters, allow summer-dormant tall fescue to be better adapted and more persistent in the southern Great Plains than traditional, summer-active types of tall fescue and other cool-season perennial grasses (Hopkins and Bhamidimarri, 2009; Malinowski et al. 2009). However there are no best-management practices that address the timing of grazing cessation as it relates to summer-dormant tall fescue stand persistence and animal production. The objectives of this study were to determine the effects of four grazing termination dates on endophyte-free ‘Flecha’ summer-dormant tall fescue forage production, animal production (average daily gain [ADG], gain, and grazing days), and tall fescue persistence (% stand and root mass)

Endophyte Status in Summer-Dormant Tall Fescue in the Southern Great Plains of USA

Non-toxic fungal endophytes provide persistence-related benefits to summer-active, continental-type tall fescue (Festuca arundinacea Schreb.), as well as reduced animal toxicosis compared to toxic endophytes. However, the benefits of fungal endophytes to summer-dormant, Mediterranean-type tall fescue persistence or production are unclear. Summer-dormant tall fescue has potential to replace traditional, annual small grain graze-out systems in the Southern Great Plains region of the USA. This region is characterized by severe water deficits accompanied by extreme heat in summer, and by relatively mild, rainy winters (Malinowski et al. 2009). Summer-active tall fescues are better suited to high rainfall areas (\u3e 900 mm annual average rainfall (AAR)) east of the 97° longitudinal meridian, while summer-dormant tall fescues are best adapted to lower rainfall areas (600 to 900 mm AAR) between the 97° and 99° longitudinal meridian (Butler et al. 2011). The objective of this field study was to determine the effects of the ‘novel’ endophyte strain AR542 on persistence of summer-dormant tall fescue ‘Flecha’ in the Southern Great Plains of the USA. Two field experiments were conducted to evaluate the effect of the novel endophyte AR542 on the survival of Flecha

Herbage and Seed From Texan Native Perennial Herbaceous Legumes

Native seed mixes for rangeland seeding, prairie restoration, or cultivated pasture can benefit from a greater variety of forbs that more closely reflect the original vegetation of the southern Great Plains. Fifteen native, perennial herbaceous legumes were collected in central Texas and evaluated for herbage production, mineral content, and fiber concentration of established plants in research plots over 2 years. Downy milk-pea (Galactia volubilis [L.] Britton) was productive, regardless of rainfall, whereas prairie acacia (Acacia angustissima [Mill.] Kuntze var. hirta [Nutt.] B.L. Rob.) and Illinois bundle-flower (Desmanthus illinoensis [Michx.] MacMill. Ex. B.L. Rob. Fernald) out-yielded others in year 3 when rainfall was the greatest. Herbage crude protein averaged approximately 100 g kg-1 for bush-clovers (Lespedeza spp.) compared to bundle-flowers (Desmanthus spp.), which exceeded 200 g kg-1; the latter also was high in herbage phosphorus. Herbage neutral detergent fiber ranged from 300 to more than 500 g kg-1, acid detergent fiber ranged from 140 to 360 g kg-1, and acid detergent lignin ranged from 36 to 140 g kg-1, a wide range from which to select if animal nutrition is a primary criterion. Seed production was evaluated within a subset of 8 entries submitted to periodic herbage removal or left intact throughout the season. Three bundle-flowers yielded the greatest mass and seed number, but were negatively affected by harvest, unlike prairie acacia. Herbage and seed characteristics indicate there are promising perennial herbaceous legumes in the southern Great Plains that can be included in native seed mixes.  The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform August 2020Legacy DOIs that must be preserved: 10.2458/azu_rangelands_v58i6_interrant

Estimation of Biomass and Canopy Height in Bermudagrass, Alfalfa, and Wheat Using Ultrasonic, Laser, and Spectral Sensors

Non-destructive biomass estimation of vegetation has been performed via remote sensing as well as physical measurements. An effective method for estimating biomass must have accuracy comparable to the accepted standard of destructive removal. Estimation or measurement of height is commonly employed to create a relationship between height and mass. This study examined several types of ground-based mobile sensing strategies for forage biomass estimation. Forage production experiments consisting of alfalfa (Medicago sativa L.), bermudagrass [Cynodon dactylon (L.) Pers.], and wheat (Triticum aestivum L.) were employed to examine sensor biomass estimation (laser, ultrasonic, and spectral) as compared to physical measurements (plate meter and meter stick) and the traditional harvest method (clipping). Predictive models were constructed via partial least squares regression and modeled estimates were compared to the physically measured biomass. Least significant difference separated mean estimates were examined to evaluate differences in the physical measurements and sensor estimates for canopy height and biomass. Differences between methods were minimal (average percent error of 11.2% for difference between predicted values versus machine and quadrat harvested biomass values (1.64 and 4.91 t·ha−1, respectively), except at the lowest measured biomass (average percent error of 89% for harvester and quad harvested biomass < 0.79 t·ha−1) and greatest measured biomass (average percent error of 18% for harvester and quad harvested biomass >6.4 t·ha−1). These data suggest that using mobile sensor-based biomass estimation models could be an effective alternative to the traditional clipping method for rapid, accurate in-field biomass estimation

Partição da biomassa e qualidade da forragem de Bahiagrass: Paspalun notatum cv. pensacola no centro-norte da Flórida = Biomass allocation and forage quality in a pensacola Bahiagrass pasture in north central Florida

Visando medir efeitos do manejo da Bahiagrass cv. pensacola (Paspalum notatum Flüggeé) na repartição de biomassa (kg ha-1) das folhas+colmos, serrapilheira, raízes+rizomas, e valor nutritivo da forragem, foi instalado um experimento próximo a Gainesville, Flórida,EUA. Tratamentos: três manejos contínuos (não intensivo, moderadamente intensivo, altamente intensivo, recebendo 40, 120, e 360 kg N ha -1 ano-1 e com lotação de 1,2; 2,4 e 3,6 UA ha-1, respectivamente) e um tratamento de manejo rotacionado (7 dias de pastejo e 21 dias de descanso), recebendo 360 kg N ha-1 ano-1 e 3,6 UA ha-1 (1 U A= 500 kg). A biomassa de raízes+rizomas foi superior a de folhas+colmos. Não houve efeito dos tratamentos na biomassa de raízes+rizomas. A biomassa de raízes+rizomas decresceu durante a estação de pastejo. A maior intensidade de manejo dos tratamentos altamente intensivo e rotacionado resultou em maior biomassa de folhas+colmos. A relação raiz/parte aérea decresceu com a intensificação do manejo. A biomassa de serrapilheira foi superior a de folhas+colmos nos tratamentos altamente intensivo e rotacionado, privilegiando a ciclagem de nutrienes via excreção animal. Os tratamentos não afetaram a FDN nem a DIVMO da forragem, masintensificação do manejo tende a elevar a DIV MO da forragem.<br><br>This experiment evaluated a pensacola Bahiagrass pasture (Paspalum notatum Flüggeé). It was conducted near Gainesville, Florida, U SA, to measure the effect of pasture management on biomass allocation (kg ha -1) of herbage, litter, root+rhizome, as well as forage quality. Treatments were three continuously stocked (low, moderate, and high,receiving 40, 120, and 360 kg N fertilizer ha -1 yr-1and with stocking rates of 1.2, 2.4, and 3.6 AU ha-1, respectively) and one rotationally stocked (RS; 7 -d grazing and 21-d rest periods; N rate of 360 kg ha-1 yr-1, 1 AU = 500 kg) pasture. The root+rhizome biomass was 4 to 12 times greater than herbage biomass. There was no effect of treatment on root+rhizome biomass. The root+rhizome biomass decreased during the grazing season. The greater manageme nt intensityimposed on high and RS pastures resulted in greater herbage biomass. The root/herbage ratio decreased with the intensification of management. The litter biomass turned to be greater than herbage biomass in the high and RS treatment, characteri zing the different cycling pattern that goes through the animal excretions. Treatments affected neither herbage NDF nor IVDOM, but increasing management intensity tended to result in high IVDOM

Partição da biomassa e qualidade da forragem de Bahiagrass: Paspalun notatum cv. pensacola no centro-norte da Flórida - DOI: 10.4025/actascianimsci.v28i4.596

This experiment evaluated a pensacola Bahiagrass pasture (Paspalum notatum Flüggeé). It was conducted near Gainesville, Florida, USA, to measure the effect of pasture management on biomass allocation (kg ha -1) of herbage, litter, root+rhizome, as well as forage quality. Treatments were three continuously stocked (low, moderate, and high, receiving 40, 120, and 360 kg N fertilizer ha-1 yr-1and with stocking rates of 1.2, 2.4, and 3.6 AU ha-1, respectively) and one rotationally stocked (RS; 7 -d grazing and 21-d rest periods; N rate of 360 kg ha-1 yr-1, 1 AU = 500 kg) pasture. The root+rhizome biomass was 4 to 12 times greater than herbage biomass. There was no effect of treatment on root+rhizome biomass. The root+rhizome biomass decreased during the grazing season. The greater manageme nt intensity imposed on high and RS pastures resulted in greater herbage biomass. The root/herbage ratio decreased with the intensification of management. The litter biomass turned to be greater than herbage biomass in the high and RS treatment, characteri zing the different cycling pattern that goes through the animal excretions. Treatments affected neither herbage NDF nor IVDOM, but increasing management intensity tended to result in high IVDOM.Visando medir efeitos do manejo da Bahiagrass cv. pensacola (Paspalum notatum Flüggeé) na repartição de biomassa (kg ha-1) das folhas+colmos, serrapilheira, raízes+rizomas, e valor nutritivo da forragem, foi instalado um experimento próximo a Gainesville, Flórida, EUA. Tratamentos: três manejos contínuos (não intensivo, moderadamente intensivo, altamente intensivo, recebendo 40, 120, e 360 kg N ha -1 ano-1 e com lotação de 1,2; 2,4 e 3,6 UA ha-1, respectivamente) e um tratamento de manejo rotacionado (7 dias de pastejo e 21 dias de descanso), recebendo 360 kg N ha-1 ano-1 e 3,6 UA ha-1 (1 U A= 500 kg). A biomassa de raízes+rizomas foi superior a de folhas+colmos. Não houve efeito dos tratamentos na biomassa de raízes+rizomas. A biomassa de raízes+rizomas decresceu durante a estação de pastejo. A maior intensidade de manejo dos tratamentos altamente intensivo e rotacionado resultou em maior biomassa de folhas+colmos. A relação raiz/parte aérea decresceu com a intensificação do manejo. A biomassa de serrapilheira foi superior a de folhas+colmos nos tratamentos altamente intensivo e rotacionado, privilegiando a ciclagem de nutrienes via excreção animal. Os tratamentos não afetaram a FDN nem a DIVMO da forragem, mas intensificação do manejo tende a elevar a DIV MO da forragem