Jerry Davis

The cat may be self-medicating.  Probably half of ornamental plants are poisonous, but they are also used medicinally in various ways.  Even belladonna, stinging nettle, etc.  I have day lilies and stray cats I take care and both are doing fine.

I wish I had this problem, rather than bare, dry shade dirt....

Plants are weird.  No 2 seeds seem to produce the same plant as the parent.  Even if they look alike, analyzing the nutritional qualities of the seeds, for instance, will show they vary from each other.

I think S Ayalp hit the crux of the problem.  Is the idea to have a commercial orchard, personal sustenance, or just gardening?  Here we don't have the same problems because orchards aren't possible (although small orchards exist in the higher mountain ranges) due to the prohibitive nature of the water supply.  However we have miles of pecan trees which obviously don't present the problem of raw fruit in the trees or on the ground.  Maybe susbstitute nut trees of various types for fruit trees although, of course, it will be a number of years to recognize the benefit.

Human urine is high in urea (nitrogen) and could burn (or fertilize) the plant.  Probably protecting the plants or getting them off the ground would be more effective.