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Paddock Size and Stocking Density Affect Spatial Heterogeneity of Grazing
Author
Barnes, Matthew K.
Norton, Brien E.
Maeno, Motoko
Malechek, John C.
Publisher
Society for Range Management
Publication Year
2008-07-01
Body

The claim that intensive rotational grazing (IRG) can sustain higher stocking rates can be partially explained by more even spatial distribution of grazing such that livestock consume forage from a greater proportion of a pasture. To test the hypothesis that utilization is more even at the higher stocking densities of smaller paddocks, mean absolute deviation (heterogeneity) of utilization estimates by plot was compared in paddocks of sizes and stocking densities representing increasing subdivision from two-paddock deferred rotation grazing (DRG) to 16-, 32-, and 64-paddock, two-cycle IRG. These 70-, 4-, 2-, and 1-ha paddocks were grazed for 7 wk, 4 d, 2 d, and 1 d, respectively, at 32 animal unit days (AUD) ha-1 during 2000 and 34 AUD ha-1 during 2001. Within IRG there was no response to the treatment gradient. After one cycle in the IRG paddocks, heterogeneity of use was generally lower than in the DRG paddocks, in both 2000 (3-11% [outlier 18%] vs. 14-19%) and 2001 (9-17% vs. 24-28%). After a second cycle in 2001, heterogeneity in half of the IRG paddocks (17-21%) was nearly as high as the early-grazed (24%), but not the late-grazed (28%), of the DRG paddocks. This lack of a stronger difference between systems was probably due to the fixed two-cycle IRG schedule and lack of plant growth during the nongrazing interval. Across both systems heterogeneity of utilization was strongly positively correlated with paddock size. Because utilization was not severely patchy in the largest treatment, the difference between systems would likely be greater in commercial-scale paddocks. Thus grazing distribution can be more even under intensive than extensive management, but this depends on how adaptively the system, particularly the aspects of timing and frequency, is managed.  The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact lbry-journals@email.arizona.edu for further information. Migrated from OJS platform August 2020

Language
en
Resource Type
Text
Document Type
Journal Issue/Article
Digital Object Identifier (DOI)
10.2111/06-155.1
Additional Information
Barnes, M. K., Norton, B. E., Maeno, M., & Malechek, J. C. (2008). Paddock size and stocking density affect spatial heterogeneity of grazing. Rangeland Ecology & Management, 61(4), 380-388.
ISSN
0022-409X
OAI Identifier
oai:repository.arizona.edu:10150/642964
Journal Volume
61
Journal Number
4
Journal Pages
380-388
Collection
Rangeland Ecology & Management (REM)
Journal Name
Rangeland Ecology & Management
Keywords
deferred rotation grazing
grazing management systems
intensive rotational grazing
livestock distribution
short-duration grazing
time control grazing