Hi Vivian,
I second what Don says. By the way your garden looks absolutely beautiful from your photo. Wonderful setting. Got green horns – what me? I’m sure you’re going to grow amazing crops with no dig. A compost mulch tends to protect the soil from erosion and compost ‘locks together’ more than soil, particularly if firm. Also plant roots can travel a fair distance laterally trough the compost which also helps to stabilise the structure. Good luck.
Jan