I find just putting well rotted horse manure,homemade compost & occasionally some bought council made compost on the soil every year is enough. Now in my 5th year of no dig & I find it incredibly easy & good to know that I’m feeding all the flora, fungi & microbiology under the ground. I don’t bring weeds seeds up to the top. I’ve not ‘fed’ my crops in the poly tunnel since it went up April ‘21, & the tomatoes,cucumbers,peppers & everything else have been phenomenal. It also locks carbon in the soil so good for the environment too. Really works for me, very little or no slug damage too as there’s nothing for them to hunker down in- no raised beds or partially rotting of chop & drop type mulches.