Heli Lad,
You are not spraying crops.
When you get to that level of flying as a commercial pilot earning your keep flying helicopters....then you might have need of these kinds of techniques.
Until then....stick to what your Instructors are teaching you while you study up on other techniques and procedures. Discuss it all with them and incorporate some of all this into your training flights to broaden your experience level but do so as part of your flying with your Instructors.
Just as I advised not getting into discussions about Long Lining....Spray flying is an altogether kettle of fish as well.
I am sure Crab will pass himself as an expert on Spraying but and German Army Flight Techiques but he does have a privileged point of view being our Resident SAR expert.