central MN, rolling land, sandy soil

I am planting fruit trees in land that was unfarmed for many years. pocket gophers are rampant.

I've tried trapping, gassing, and poisoning with very limited effectiveness. the only thing that seems to work is plowing the area very deep and then regular mowing.

so far they haven't attacked the area where I planted 50 fruit trees last year although they are in adjacent areas so it's only a matter of time.

questions:

1. is there some truly effective approach to eradicating these things given they'll always be in some adjacent fallow fields off my property?

2. do they like fruit trees? (they killed hundreds of evergreen trees I planted several years ago)

thx in advance for any help.