Grass clipping mixed into the soil, not a mulch

Is it wise?

I have some old grass clippings, at least a year but looking today the top layer is bone dry, I will need to dig and there is some horse and shavings mixed here and there.

I want to grow potatoes and raspberries. Could I mix the grass clippings into my soil? then mulch the potatoes or is that a nitrogen overdose?

 

Thank you, Ill try it as just want to add something more. I do half a goo depth of topsoil but no depth as such. This winter I need to dump it with manure haha

 

Doesn't grass attract wire worm, a horrible pest to potatoes?

 

No idea thats why Im asking!