Question about Precision Farming Crop sensor

[Kiptanoi]

Hello, I just have a small question about that Crop sensor.
If I am understanding it right, it helps only when I fertilizing a field?

If I have this tool: John Deere R732i PowrSpray with See & Spray on.
And doing liquid fertilizer on a field, then it say in my info tab
"Increasing Nitrogen level to optimal value for "Grass" on Loamy Sand"
Application Rate: Auto

Do I then really also need to buy the ISARIA PRO Active/COMPACT sensor to get that to work correct?

I would really be happy if someone could explain in detail, when I need the sensor and when I need it to be turned on, and when I don't need the sensors turned on. (What tool/implements do need it and what tool/implements don't need sensors )

[Guil]

See n spray is really only for herbicide usage afaik.

[Motologist]

Correct, crop sensors only help when fertilizing. They do not help with herbicide.

Turn the crop sensor on whenever you are fertilizing with a fertilizer spreader or sprayer. From experimentation, using the crop sensor when using a seeder or planter that both seeds and fertilizes doesn't provide 100% accuracy. For nitrogen accuracy, apply fertilizer after seeding.

See n' Spray helps with both fertilizer and herbicide. If you use a crop sensor on your tractor combined with a sprayer that has See n' Spray, you won't waste fertilizer when overlapping areas you've already covered.

[Guil]

Base game stops using fert or herbicide on land you have already covered afaik so See n' Spray is irrelevant for fert.
The benefit of See n' Spray is that it will only use herb on growing weeds