If it is necessary to improve on the control achieved by a single application, the split application technique can be utilized.
For either procedure, plowing the soil just prior to application can bring moist soil to the top which will can result in a more effective sealing of the surface following application.
In general, the deeper the fumigant is placed the more effective the application.
Although University of California guidelines call for a shank spacing of 12 inches or less, larger distances are often utilized in commercial practice allowing a larger area to be treated in less time.
Sealing of the soil surface after application improves control in the upper layers of soil by slowing the rate at which the fumigant moves through this area.