e with fumigation equipment in place of traditional single depth shanks to provide better distribution in soil of Metam-sodium products which on their own will only diffuse about 4 inches through the soil.

　　These shanks have 3 spray nozzles in the back to inject product at 3 different depths.

　　Behind each of the wedges on this shank is a spray nozzle. The wedges help provide better mixing of the product in soil, but also require more powerful equipment to pull them through the field than more streamlined shanks.

　　This spray rake has nozzles at 4 inch spacings. It is designed to be pulled through a preformed bed followed by a bed shaper to smooth and seal the soil surface.

参考文献：
1.http://trc.ucdavis.edu/biosci10v/courses/204nem/CHEM/ESHANK.htm