Cattle grazing for brush control.  Guggenmoos, S., Karpovich, K.G.

Maintenance of a power line compatible plant community on right of ways requires periodic interventions.  The intervention normally consists of mechanical clearing followed by herbicide applications.  A distribution line right of way southwest of Camrose, Alberta was recleared in 1986.  Cattle were used to graze .58 ha of right of way in 1988 and 1989.  Grazing area for the cattle was restricted by the placement of electric fences.  The landowner decided when feed remaining on the right of way was limiting to his cattle and released them to other pasture.  Regrowth height of poplar spp averaged 77cm before initiation of grazing.  On November 14, 1989 six randomly selected 40 square metre plots were evaluated for the number of poplar stems and the average height.  The same observations were made in an adjacent ungrazed check.

Impact of 2 seasons grazing

Plot Sprouts/40 sq. m1 % of Check Average Height (cm) 1 % of Check
Check 176 140
1 110 62.5 90 64.3
2 95 54.0 65 46.4
3 89 50.6 60 42.9
4 151 85.8 50 35.7
5 103 58.5 60 42.9
6 234 132.9 99 70.7

1 Student T-test t.05 indicates check and treated sample values should not be considered different

The grazing appeared to decrease the density of the regrowth and halve the height.  A Student T-test (t.05) for small sample size however, does not support a conclusion of differences in density nor average height between the grazed areas and the check plot.  This result does not justify the additional costs in labour and fencing involved in forcing the cattle to graze the right of way.

(TransAlta Utilities, Sherwood Park, Alberta)