Effects of time-controlled grazing on runoff and sediment loss

Loading...
Thumbnail Image
File version
Author(s)
Sanjari, Gholamreza
Yu, Bofu
Ghadiri, Hossein
Ciesiolka, Cyril AA
Rose, Calvin W
Griffith University Author(s)
Primary Supervisor
Other Supervisors
Editor(s)
Date
2009
Size

281051 bytes

File type(s)

application/pdf

Location
License
Abstract

The time-controlled grazing (TC grazing) has become popular in Australia and elsewhere in the world to provide graziers and ranchers with improved productivity over traditional practices. However, this grazing system, which involves short periods of intensive grazing, has raised concerns about the sustainability and environmental impacts on water and soil resources and ecosystem health generally. A runoff catchment experiment at the catchment scale was established on the grazing property 'Currajong' in the south-east region of Queensland, Australia to investigate the effects of continuous and TC grazing on runoff and sediment generation from 2001 to 2006. Sediment loss reduced significantly under TC grazing compared with continuous grazing irrespective of the size of runoff events. This effect is more pronounced in the catchments with soils of gentler slopes and greater depths. The reduction in soil erosion was achieved despite the fact that the increase in ground cover under TC grazing had little effect on runoff coefficient or runoff. Decrease in runoff in relation to the increase in surface cover only occurred for small events, whereas for large rainfall events, runoff generated irrespective of the level of ground cover. This study showed that ground cover is a key driver in reducing sediment concentration, resulting in a significantly lower sediment loss under TC grazing. In the study area a minimum of 70% of surface cover as threshold appears to be needed to efficiently protect the soil surface from erosive forces of rain and runoff and to control soil erosion. The results also indicate that TC grazing has a superior capability to produce and maintain a higher level of ground cover (up to 90%) than continuous grazing (up to 65%). The long rest periods in TC grazing are seen as being the major contributor to soil and pasture recovery after intensive defoliations by grazing animals, leading to an increase in above-ground organicmaterial and thus surface cover over time.

Journal Title

Australian Journal of Soil Research

Conference Title
Book Title
Edition
Volume

47

Issue

8

Thesis Type
Degree Program
School
Publisher link
Patent number
Funder(s)
Grant identifier(s)
Rights Statement
Rights Statement

© 2009 CSIRO. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher. Please refer to the journal's website for access to the definitive, published version.

Item Access Status
Note
Access the data
Related item(s)
Subject

Natural resource management

Soil sciences

Persistent link to this record
Citation
Collections