increasing soil acidity with grass clippings?

My soil has a high shell content and is alkaline, the testing kit I used did not have a green as green as my soil gave.
I found this about potato scab http://www.dgsgardening.btinternet.co.uk/potatoscab.htm it suggests adding grass clippings to increase acidity.
Should i add grass clippings for all my crops?
ta

 

As far as I understand it, the decomposition of green material consumes nitrogen from the soil. I'd avoid using clippings on areas where you'll be planting veg with a high nitrogen demand e.g. sprouts, cabbage, beetroot, leeks.
You'll increase acidity if you add well rotted compost and old growbag compost year by year. Unless you have a problem with scab, I'd suggest you compost your grass clippings.
I now grow only early tatties and they get planted before I've started mowing the lawns, though in the past I have used clippings when planting maincrop.

 

My tatties are suffering from scab, grass cuttings on the ground thats going to grow them next year then?

 

The advice I was given years ago was to put fresh grass cuttings in the drills when I sowed the seed.
Quite apart from the slight acid boost, the cuttings help conserve moisture during the critical first few weeks of development.