Physical description

9 slides labelled, describing the use of Rock Dust Nov 86. Ways of applying Rock Dust - Proximity of holes of aerator. 2. Rock Dust Application - Hole made by soil aerator (Allen Miller). 3. - Hole made by soil aerator. 4. Rock Dust - Aerator pattern. 5. - Aerator hole layout. 6. - Soil aerator (Allen Miller). 7. - Aerator tine layout. 8. - Tine layout. 9. - Width of aerator holes.