Forcing N deficiency as a way of managing plant size?

[geotek]

I have a neighbor who intentionally forces N deficiency by not adding any N to his potting mix that he reuses from year to year as a means of controlling plant size. He adds lots of P and some ground shells for Ca and Mg.
The plants are 1 to 2' tall and all show the stunting and pale leaves of N deficiency but are flowering heavily. Has anyone else heard of this method? Just curious. It seems a little bizarre to me.