a lely is the wrong tool for corn, the bend of the tine is ideal for taking out branching root system such as corn but will leave tap roots alone. We use a lely exclusively for beans because beans are taproots and our primary weeds are grasses.

My parents wrote a 3 part series on organic weed control about 10 years ago, it takes in everything that they had learned in 15 years of organic production and principles from before the green revolution when steel was all farmers had.

http://lakevieworganicgrain.com/pub_art1/The%20basics%20of%20effective%20tillage%20techniques.pdf
http://lakevieworganicgrain.com/pub_art1/Blind%20cultivation.pdf
http://lakevieworganicgrain.com/pub_art1/In-row%20cultivation.pdf

We still follow roughly that pattern today and it still works well