When dragged through the ground , it leaves a channel deep under the ground , and this acts as a drain .
It is a very deep plow , with a torpedo - shaped or wedge - shaped tip , and a narrow blade connecting this to the body .
When dragged through the ground , plow leaves a channel deep under the ground , and this acts as a drain .
It is a very deep plow , with a torpedo - shaped or wedge - shaped tip , and a narrow blade connecting this to the body .