scholarly journals Late Summer Prescribed Fire and Fall Herbicide Application Show Strong Suppressive Effects on Sericea Lespedeza Frequency and Vigor

Author(s):  
G. A. Gatson ◽  
W. H. Fick ◽  
W. W. Hsu ◽  
K C Olson
Author(s):  
J A Alexander ◽  
W H Fick ◽  
S B Ogden ◽  
D A Haukos ◽  
J Lemmon ◽  
...  

Abstract The predominant grazing management practice of the Kansas Flint Hills involves annual prescribed burning in March or April with post-fire grazing by yearling beef cattle at a high stocking density from April to August. There has been a dramatic increase in sericea lespedeza (Lespedeza cuneata [Dumont] G. Don) coincident with this temporally-focused use of prescribed fire in the Flint Hills region. The species is an aggressive invader and a statewide noxious weed in Kansas. Control has generally been attempted using repeated herbicide applications. This approach has not limited proliferation of sericea lespedeza and resulted in collateral damage to non-target flora and fauna. Alternative timing of prescribed fire has not been evaluated for its control. Our objectives for this 4-yr experiment were to (1) document the effects of prescribed burning during early April, early August, or early September on vigor of sericea lespedeza, standing forage biomass, and basal cover of native graminoids, forbs, and shrubs and (2) measure responses to fire regimes by grassland bird and butterfly communities. Whole-plant dry mass, basal cover, and seed production of sericea lespedeza were markedly less (P < 0.01) in areas treated with prescribed fire in August or September compared with April. Forage biomass did not differ (P ≥ 0.43) among treatments when measured during July; moreover, frequencies of bare soil, litter, and total basal plant cover were not different (P ≥ 0.29) among treatments. Combined basal covers of C4 grasses, C3 grasses, annual grasses, forbs, and shrubs also did not differ (P ≥ 0.11) between treatments. Densities of grasshopper sparrow (Ammodramus savannarum), dickcissel (Spiza americana), and eastern meadowlark (Sturnella magna) were not negatively affected (P > 0.10) by mid-summer or late-summer fires relative to early-spring fires. There were no differences (P > 0.10) in densities of grassland-specialist butterfly species across fire regimes. Under the conditions of our experiment, prescribed burning during summer produced no detrimental effects on forage production, desirable non-target plant species, grassland birds, or butterfly communities but had strong suppressive effects on sericea lespedeza. Additional research is warranted to investigate how to best incorporate late-summer prescribed fire into common grazing-management practices in the Kansas Flint Hills.


2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 151-151
Author(s):  
K C Olson

Abstract North-American tallgrass prairie provides an array of ecosystem services including carbon sequestration, biodiversity preservation, and forage for grazing livestock. Once covering 68 million ha, only 4% remains today. The largest remnant (~1.5 million ha) lies in the Kansas Flint Hills, home to ~1.3 million yearling cattle and ~90,000 beef cows annually. Unfortunately, the functionality of this ecosystem is threatened by an exotic invader - sericea lespedeza (Lespedeza cuneata). Known colloquially as sericea, it is a perennial forb with prodigious capacity to proliferate. Sericea selection by grazing cattle is poor; condensed-tannin concentrations in wild-type sericea approach 20% of plant DM. Total-tract N digestibility by steers consuming sericea-contaminated tallgrass-prairie hay was documented at < 0%. Sericea control has been attempted using herbicides. This has not limited proliferation and has resulted in collateral damage to non-target lifeforms. Attempts to naturalize sericea to the ecosystem via enhanced herbivory were evaluated. Supplementation of beef cow diets with tannin-binding feedstuffs resulted in ≥29% increases in sericea selection compared with non-supplemented cows. Co-grazing beef cows and goats was associated with >20% more defoliation of sericea than beef-cow grazing alone. Sequential grazing of yearling steers followed by mature ewes resulted in >92% defoliation of sericea compared with < 2% in pastures grazed by steers alone. Unfortunately, widespread adoption of these techniques by the ranching community hasn’t occurred because of costs or logistical constraints. More recently, prescribed fire as a low-cost means of control was evaluated. Prescribed fires in late summer greatly diminished sericea proliferation compared with prescribed fires in spring (i.e., traditional prescribed-fire season). No changes in peak forage biomass or C4 grass-species abundance were observed; moreover, native legumes and nectar-producing forbs increased ≥2-fold in response to summer fire. Cultural acceptability of prescribed fire in the region is high; significant adoption by the ranching community has been observed.


2007 ◽  
Vol 21 (4) ◽  
pp. 1071-1081 ◽  
Author(s):  
Roger L. Sheley ◽  
Michael F. Carpinelli ◽  
Kimberly J. Reever Morghan

Medusahead is an introduced, winter-annual grass covering millions of hectares of the semiarid West. It forms exclusive stands and has a dense thatch cover that resists the establishment of desirable species. Prescribed fire can remove medusahead litter and improve plant establishment. Medusahead control is fundamental to establishing desirable species that will, in turn, resist further invasion. Imazapic is an effective herbicide for control of medusahead, but more information is needed on its effects on desirable species. Our objectives were to test how imazapic application rate and timing affected medusahead, seeded desirable species, and other nontarget vegetation on burned and unburned rangeland in southeast Oregon. We burned existing medusahead infestations at two different sites in June 2003. Following the burn, imazapic was applied at rates of 0, 35, 70, 105, 140, 175, and 210 g ai/ha between July and October of 2003 in a randomized strip-plot design. In November 2003, monocultures of seven desirable species were drill-seeded across the imazapic treated areas. Data on cover and density of medusahead and seeded species were collected in 2004 and 2005. Cover data of nontarget species were collected in the summer of 2005. Medusahead cover was highest in control plots and lowest in plots that received the highest herbicide application rates. Medusahead cover was lower in burned plots. The effect of imazapic on nontarget vegetation was less clear. Seeded species established in the study plots, but their response to herbicide rate showed few consistent patterns; some of the seeded species showed little response to herbicide, whereas others appeared to establish best at different herbicide rates, depending on site and whether the plots were burned or unburned. Site and burn treatment also affected how imazapic rate or application month influenced cover of perennial or annual grasses or forbs.


Author(s):  
Z M Duncan ◽  
A J Tajchman ◽  
M P Ramirez ◽  
J Lemmon ◽  
W R Hollenbeck ◽  
...  

Abstract Recent research demonstrated that mid- or late-summer prescribed fires can be employed to manage sericea lespedeza (Lespedeza cuneata) infestations in the Kansas Flint Hills. The effects of prescribed fire applied during the growing season (i.e., August to October) on grazing performance of yearling cattle have not been evaluated. Native pastures (n = 18; 22 ± 4.0 ha) were grouped by watershed and assigned randomly to 1 of 3 prescribed-fire treatments: spring (7 April ± 2.1 d), summer (21 August ± 5.7 d), or autumn (2 October ± 9.9 d). Yearling beef cattle were grazed from May to August at a targeted stocking density of 280 kg live-weight ˖ ha -1 following prescribed fire application. Forage biomass accumulations, soil cover, plant species composition, and root carbohydrate concentrations in four native plant species were evaluated. Total BW gains and ADG were greater (P = 0.01) for cattle that grazed the spring and summer prescribed-fire treatments compared with those that grazed the autumn prescribed-fire treatment. As a result, final BW were greater (P = 0.04) in the spring and summer treatments than the autumn treatment. Conversely, forage biomass accumulations did not differ (P = 0.91) between fire regimes. Proportions of bare soil were greater (P < 0.01) in the spring treatment compared with the summer and autumn treatments, whereas proportions of litter on the soil surface were greater (P < 0.01) in summer- and autumn-burned pastures compared with spring-burned pastures. Total basal cover of graminoids and forbs did not differ (P ≤ 0.15) between prescribed fire treatments. Likewise, total basal cover of C3 or C4 perennial grasses did not differ (P ≥ 0.23) between prescribed fire treatments. No treatment differences (P = 0.24) in root starch or root water-soluble carbohydrate concentrations in big bluestem (Andropogon gerardii), little bluestem (Schizachyrium scoparium), Indiangrass (Sorghastrum nutans), or purple prairieclover (Dalea purpurea) were detected. These data were interpreted to suggest that summer or autumn prescribed fire can be applied without reducing forage biomass accumulations, root carbohydrate concentrations in key native plant species, or considerably altering native plant populations compared with conventional spring-season prescribed fire; however, summer prescribed fire could be favored over spring or autumn prescribed fire to both maintain stocker cattle growth performance and to achieve control over sericea lespedeza.


Author(s):  
J. A. Alexander ◽  
W. H. Fick ◽  
J. Lemmon ◽  
G. A. Gatson ◽  
K C Olson

2006 ◽  
Vol 36 (17) ◽  
pp. 12
Author(s):  
MICHAEL E. PICHICHERO
Keyword(s):  

2020 ◽  
pp. 637-656 ◽  
Author(s):  
Marco Medici ◽  
Søren Marcus Pedersen ◽  
Giacomo Carli ◽  
Maria Rita Tagliaventi

The purpose of this study is to analyse the environmental benefits of precision agriculture technology adoption obtained from the mitigation of negative environmental impacts of agricultural inputs in modern farming. Our literature review of the environmental benefits related to the adoption of precision agriculture solutions is aimed at raising farmers' and other stakeholders' awareness of the actual environmental impacts from this set of new technologies. Existing studies were categorised according to the environmental impacts of different agricultural activities: nitrogen application, lime application, pesticide application, manure application and herbicide application. Our findings highlighted the effects of the reduction of input application rates and the consequent impacts on climate, soil, water and biodiversity. Policy makers can benefit from the outcomes of this study developing an understanding of the environmental impact of precision agriculture in order to promote and support initiatives aimed at fostering sustainable agriculture.


2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.


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