Even though you can create a gerund by using growing, it sounds like an outside stimulus rather than an inside act growth. I would stick with growth.
You could, however, use growing to refer to plants.
Nitrogen in the soil is essential for plant growing (if you are a farmer and want to grow plants). Even in this example, where it would be acceptable to say that because the farmer will add nitrogen to his soil if needed (outside stimulus) to make his plant growing endeavor successful, growth would probably be used.
Nitrogen in the soil is essential for plant growth. (It would be understood that if there was not enough nitrogen in the soil, the farmer would add some, if he read the sentence, tests his soil and has common sense.)
Use growth--even though grammatically you can come up with an argument as to why growing would not be wrong.