Over grazing
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The grazing pressure on grasslands is very high. In semi arid areas, carrying capacity in good range land is 1 adult cow unit (ACU) /ha but the actual pressure is 3.2 ACU/ha. But in arid areas, carrying capacity is 1 - 4 ACU / ha as against the actual pressure of 0.2 - 0.5 ACU / ha.
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Due to over grazing run off and soil erosion are high. Results from IGFRI indicated that there was 41% run off from bare soil where as in the improved grass land vegetation, the run off was only 6.5 %. Over grazing also results in a shift in the natural succession (as seen in 3 d). Over grazing also results in greater run off and soil loss. Eg.
Results from IGFRI, Jhansi (96 -97)
- Total quantum of water received through rainfall - 6035 cum/ha
- Grazing pressure 1.5 ACU/ha. in grazing systems
Grazing system
|
Total run off (cum/ha)
|
Soil loss (t/ha)
|
Run off Co eff (%)
|
Rotational grazing
|
376
|
0.17
|
6.2
|
Differed grazing
|
423
|
0.26
|
7.0
|
Continuous grazing
|
457
|
0.46
|
7.5
|
Cut and carry system
|
383
|
0.13
|
6.3
|
Bare plots
|
1173
|
0.68
|
19.4
|
|
Last modified: Thursday, 24 November 2011, 9:17 AM