Grasslands of the World.pdf - Disasters and Conflicts - UNEP

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TABLE 4.4
Complexity levels of grazing management in Patagonia .
Grasslands of the world
Level Description Limitations Application
0 Traditional management
Continuous grazing with subjectively estimated,
fixed stocking rates
1 Continuous flexible stocking
Range evaluation provides objective information
for animal allocation . Range monitoring allows for
yearly adjustments, to deal with climatic variation.
Opportunistic rest of paddocks in rainy years
Fencing of meadows and separate management
2 Deferred rotation systems
Schematic rotation with low animal concentration
(less than 50% of the farm is rested at any time)
3 Specialized grazing systems
Schematic rotation with high animal concentration.
(High intensity-low frequency, low intensity-low
frequency and short duration grazing )
SOURCE: Golluscio et al., 1999, who adapted from a 1993 unpublished report.
Overgrazing in 50% of cases.
Land degradation. Low
lambing rates, with high
mortality.
Moderate continuous grazing
could promote undesirable
transitions in some
environments.
Deferred rotation did not
produce the results expected.
Moderate managerial skills
are required.
High requirement for fencing
and managerial skills.
Limited information about
the benefits of the practice.
97% of the farms
of Argentinian
Patagonia
2 grazing studies and
more than 200 farms
with grazing plans
2 grazing studies
5 farms
3 farms
ized continuous overgrazing (Borrelli and Oliva, 1999), identified as the most
important cause of range degradation elsewhere (Heady and Child, 1994).
Simple Level-2 rotational grazing systems (Table 4.4) were tested in southern
Patagonia , but the advantage of changing from Level 1 was not evident
(Borrelli, 1999). Only opportunistic rest of some paddocks and fencing of
meadows proved to be worthwhile “sophistication” in grazing management .
Intensive grazing of fenced meadows showed impressive results in terms of
sheep production in NW Patagonia (Giraudo et al., 1996).
More specialized grazing systems (Level 3-type ) are regarded as promising
by researchers of the University of Buenos Aires on a large farm in NW
Chubut, Argentina (Paruelo, Golluscio and Deregibus, 1992). The generalized
adoption of these systems is limited by: scarce information regarding responses
in other environments; the limited availability of paddocks for complex
rotations; and the lack of managerial skills of most farmers. In the last decades
there has been a debate in the range management literature about grazing
systems (Kothmann, 1984) and the value of the optimal stocking rate concept
(e.g. Ash and Stafford-Smith, 1996; Stafford-Smith, 1996). As an example,
continuous moderate grazing has been shown as beneficial for combating
undesirable shrub invasions (Westoby, Walker and Noy Meir, 1989). Many
authors have considered that defoliation frequency was more important than
defoliation intensity for proper grazing management , and proposed specialized
grazing systems (Kothmann, 1984). Stafford-Smith (1996) pointed out that
both temporal and spatial heterogeneity limit the possibility of controlling
grazing intensity in continuous grazing treatments. However, for Patagonian