Contrast between adaptive multi-paddock and traditional grazing in Chilean Patagonian grasslands
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Date
2019
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Abstract
The objective of the study was to compare grassland
characteristics under two different grazing managements: adaptive multi-paddock (AMP)
and traditional (semi-continuous summer-winter rotation) grazing (TRAD). The
Ecological Outcome Verification monitoring system (Savory Institute, 2018) was used
on six ranches, in the Magallanes Region of Chile. Using satellite images, at least five
sampling locations were chosen in each ranch, looking for areas where the neighboring
ranches had similar slope and sun exposure. One location in each ranch (n=6) was
randomly chosen and paired samples were evaluated in the AMP ranch and its
traditional-grazing neighbor. In each location, two 25 m vegetation transects and one 25
m soil-health transect were evaluated. Additionally, three soil samples were taken, homogenized by depth (0 to 10, 10 to 20 and 20 to 30 cm) and measured for apparent
density and organic matter content. Traditional grazing systems had more bare ground
(P<0.05). Contextually undesirable species tended (P<0.1) to be 30.6% greater in
traditional grazing. A time regression tended (P=0.1) to show a cover difference of
Hieracium pilosella (undesirable specie in Patagonia) between AMP and TRAD
increased by 4 percentage points per year. Among pasture health indicators, AMP
tended to have greater plant litter and dung decomposition (P=0.1 for both), and had
greater litter incorporation (P<0.05), contextually undesirable species (P<0.05) and
Ecological Health Index (P<0.05). Soil organic matter content was greater (P<0.05) for
AMP than TRAD on the 20-30 cm depth. In conclusion, AMP grazing might be a useful
tool to improve pasture health, soil cover and organic matter content, and to reduce
undesirable species.The objective of the study was to compare grassland
characteristics under two different grazing managements: adaptive multi-paddock (AMP)
and traditional (semi-continuous summer-winter rotation) grazing (TRAD). The
Ecological Outcome Verification monitoring system (Savory Institute, 2018) was used
on six ranches, in the Magallanes Region of Chile. Using satellite images, at least five
sampling locations were chosen in each ranch, looking for areas where the neighboring
ranches had similar slope and sun exposure. One location in each ranch (n=6) was
randomly chosen and paired samples were evaluated in the AMP ranch and its
traditional-grazing neighbor. In each location, two 25 m vegetation transects and one 25
m soil-health transect were evaluated. Additionally, three soil samples were taken, homogenized by depth (0 to 10, 10 to 20 and 20 to 30 cm) and measured for apparent
density and organic matter content. Traditional grazing systems had more bare ground
(P<0.05). Contextually undesirable species tended (P<0.1) to be 30.6% greater in
traditional grazing. A time regression tended (P=0.1) to show a cover difference of
Hieracium pilosella (undesirable specie in Patagonia) between AMP and TRAD
increased by 4 percentage points per year. Among pasture health indicators, AMP
tended to have greater plant litter and dung decomposition (P=0.1 for both), and had
greater litter incorporation (P<0.05), contextually undesirable species (P<0.05) and
Ecological Health Index (P<0.05). Soil organic matter content was greater (P<0.05) for
AMP than TRAD on the 20-30 cm depth. In conclusion, AMP grazing might be a useful
tool to improve pasture health, soil cover and organic matter content, and to reduce
undesirable species.The objective of the study was to compare grassland
characteristics under two different grazing managements: adaptive multi-paddock (AMP)
and traditional (semi-continuous summer-winter rotation) grazing (TRAD). The
Ecological Outcome Verification monitoring system (Savory Institute, 2018) was used
on six ranches, in the Magallanes Region of Chile. Using satellite images, at least five
sampling locations were chosen in each ranch, looking for areas where the neighboring
ranches had similar slope and sun exposure. One location in each ranch (n=6) was
randomly chosen and paired samples were evaluated in the AMP ranch and its
traditional-grazing neighbor. In each location, two 25 m vegetation transects and one 25
m soil-health transect were evaluated. Additionally, three soil samples were taken, homogenized by depth (0 to 10, 10 to 20 and 20 to 30 cm) and measured for apparent
density and organic matter content. Traditional grazing systems had more bare ground
(P<0.05). Contextually undesirable species tended (P<0.1) to be 30.6% greater in
traditional grazing. A time regression tended (P=0.1) to show a cover difference of
Hieracium pilosella (undesirable specie in Patagonia) between AMP and TRAD
increased by 4 percentage points per year. Among pasture health indicators, AMP
tended to have greater plant litter and dung decomposition (P=0.1 for both), and had
greater litter incorporation (P<0.05), contextually undesirable species (P<0.05) and
Ecological Health Index (P<0.05). Soil organic matter content was greater (P<0.05) for
AMP than TRAD on the 20-30 cm depth. In conclusion, AMP grazing might be a useful
tool to improve pasture health, soil cover and organic matter content, and to reduce
undesirable species.
Description
Tesis (Magíster en Sistemas de Producción Animal)--Pontificia Universidad Católica de Chile, 2019