SOIL TYPE | SOIL TEMPERATURE (F) | SOIL TEMPERATURE (C) | % SOIL MOISTURE | RATE POUNDS/ ACRE |
Sand | 40-77 | 5-25 | 2-6 | 200 |
Loamy Sand | 40-77 | 5-25 | 3-8 | 200 |
Sandy Loam | 40-77 | 5-25 | 4-10 | 200 |
  | 40-77 | 5-25 | 10-12 | 300 |
Loam | 40-77 | 5-25 | 6-14 | 300 |
  | 40-77 | 5-25 | 14-18 | 400 |
Clay Loam | 50-68 | 10-20 | 8-12 | 300 |
  | 50-68 | 10-20 | 12-18 | 350 |
  | 50-68 | 10-20 | 18-22 | 400 |
Clay | 50-68 | 10-20 | 15-22 | 400 |
  | 50-68 | 10-20 | 22-35 | 500 |
The effectiveness of methyl bromide is affected by soil type, temperature and moisture which are related to the ability of the product to move through the air in soil pore spaces.
The table indicates optimum levels for fumigation effectiveness as specified in University of California publications. In actual practice, the rates used may vary from those indicated in the table. Outside the levels indicated, the fumigant will not move as well through the soil. As indicated by the table, in finer textured (those containing more silt and clay), and wetter soils, higher rates are needed to obtain similar results.