Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses

Defoliation intensity and timing are two important factors determining plants response to grazing. These factors can be managed by adjusting stocking rate and applying a grazing strategy. In a 6-yr clipping experiment conducted in northwestern Argentina, we assessed the effect of different defoliati...

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Main Authors: Quiroga, Raul Emiliano, Blanco, Lisandro Javier, Namur, Pedro Ramón
Format: info:ar-repo/semantics/artículo
Language:Inglés
Published: 2018
Subjects:
Online Access:http://hdl.handle.net/20.500.12123/2740
https://www.sciencedirect.com/science/article/pii/S1550742417300957
https://doi.org/10.1016/j.rama.2017.09.002
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author Quiroga, Raul Emiliano
Blanco, Lisandro Javier
Namur, Pedro Ramón
author_browse Blanco, Lisandro Javier
Namur, Pedro Ramón
Quiroga, Raul Emiliano
author_facet Quiroga, Raul Emiliano
Blanco, Lisandro Javier
Namur, Pedro Ramón
author_sort Quiroga, Raul Emiliano
collection INTA Digital
description Defoliation intensity and timing are two important factors determining plants response to grazing. These factors can be managed by adjusting stocking rate and applying a grazing strategy. In a 6-yr clipping experiment conducted in northwestern Argentina, we assessed the effect of different defoliation intensities (~ 30%, ~ 50%, and ~ 70% removal of the annually produced aboveground biomass) and simulated grazing strategies (continuous grazing, two-paddock rest-rotation, three-paddock rest-rotation, dormant season grazing) on plots of three C4 native bunchgrasses (Pappophorum vaginatum, Trichloris crinita, and Digitaria californica). Response variables were mean and trend of clipped-off biomass during the 6 yr of treatments, number of inflorescences, and aboveground biomass produced on the year following treatments end (to evaluate residual effect of treatments). Results were species dependent. Mean clipped-off biomass increased with defoliation intensity in T. crinita and D. californica. However, defoliation intensity negatively affected clipped-off biomass trend in T. crinita and the production of P. vaginatum and T. crinita during “residual effect” evaluation. The three species responded positively at least in one response variable to the amount of rest periods in the grazing strategy. Our results are not fully consistent with the concept that forage production is more influenced by defoliation intensity than by grazing strategy: In two of the three species, grazing strategy presented greater impact on response variables than defoliation intensity. When significant “defoliation intensity × grazing strategy” was detected, intensity tended to be more detrimental as grazing strategy allows fewer rest periods. We observed a residual effect of treatments in the three species (generally, negative effect of defoliation intensity and positive effect of grazing strategies with more rest periods). Our results show that dormant season utilization and rest periods are beneficial for maximizing mean clipped-off biomass and ensuring clipped-off biomass trend. High defoliation intensities can maximize short-term clipped-off biomass, but it may produce negative residual effects and trends.
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institution Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina)
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spelling INTA27402025-02-19T14:14:31Z Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses Quiroga, Raul Emiliano Blanco, Lisandro Javier Namur, Pedro Ramón Tierras de Pastos Defoliación Pastoreo Digitaria Forrajes Rangelands Defoliation Grazing Forage Digitaria californica Pappophorum vaginatum Trichloris Crinita Defoliation intensity and timing are two important factors determining plants response to grazing. These factors can be managed by adjusting stocking rate and applying a grazing strategy. In a 6-yr clipping experiment conducted in northwestern Argentina, we assessed the effect of different defoliation intensities (~ 30%, ~ 50%, and ~ 70% removal of the annually produced aboveground biomass) and simulated grazing strategies (continuous grazing, two-paddock rest-rotation, three-paddock rest-rotation, dormant season grazing) on plots of three C4 native bunchgrasses (Pappophorum vaginatum, Trichloris crinita, and Digitaria californica). Response variables were mean and trend of clipped-off biomass during the 6 yr of treatments, number of inflorescences, and aboveground biomass produced on the year following treatments end (to evaluate residual effect of treatments). Results were species dependent. Mean clipped-off biomass increased with defoliation intensity in T. crinita and D. californica. However, defoliation intensity negatively affected clipped-off biomass trend in T. crinita and the production of P. vaginatum and T. crinita during “residual effect” evaluation. The three species responded positively at least in one response variable to the amount of rest periods in the grazing strategy. Our results are not fully consistent with the concept that forage production is more influenced by defoliation intensity than by grazing strategy: In two of the three species, grazing strategy presented greater impact on response variables than defoliation intensity. When significant “defoliation intensity × grazing strategy” was detected, intensity tended to be more detrimental as grazing strategy allows fewer rest periods. We observed a residual effect of treatments in the three species (generally, negative effect of defoliation intensity and positive effect of grazing strategies with more rest periods). Our results show that dormant season utilization and rest periods are beneficial for maximizing mean clipped-off biomass and ensuring clipped-off biomass trend. High defoliation intensities can maximize short-term clipped-off biomass, but it may produce negative residual effects and trends. EEA Catamarca Fil: Quiroga, Raul Emiliano. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Catamarca; Argentina Fil: Blanco, Lisandro Javier. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja; Argentina Fil: Namur, Pedro Ramón. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja; Argentina 2018-07-06T15:15:34Z 2018-07-06T15:15:34Z 2018-01 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/2740 https://www.sciencedirect.com/science/article/pii/S1550742417300957 1550-7424 1551-5028 https://doi.org/10.1016/j.rama.2017.09.002 eng info:eu-repo/semantics/restrictedAccess application/pdf Rangeland Ecology & Management 71 (1) : 58-66 (January 2018)
spellingShingle Tierras de Pastos
Defoliación
Pastoreo
Digitaria
Forrajes
Rangelands
Defoliation
Grazing
Forage
Digitaria californica
Pappophorum vaginatum
Trichloris Crinita
Quiroga, Raul Emiliano
Blanco, Lisandro Javier
Namur, Pedro Ramón
Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses
title Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses
title_full Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses
title_fullStr Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses
title_full_unstemmed Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses
title_short Defoliation intensity and simulated grazing strategy effects on three C4 rangeland bunchgrasses
title_sort defoliation intensity and simulated grazing strategy effects on three c4 rangeland bunchgrasses
topic Tierras de Pastos
Defoliación
Pastoreo
Digitaria
Forrajes
Rangelands
Defoliation
Grazing
Forage
Digitaria californica
Pappophorum vaginatum
Trichloris Crinita
url http://hdl.handle.net/20.500.12123/2740
https://www.sciencedirect.com/science/article/pii/S1550742417300957
https://doi.org/10.1016/j.rama.2017.09.002
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AT blancolisandrojavier defoliationintensityandsimulatedgrazingstrategyeffectsonthreec4rangelandbunchgrasses
AT namurpedroramon defoliationintensityandsimulatedgrazingstrategyeffectsonthreec4rangelandbunchgrasses