Simply remove that cats faeces, though of they are defecating now that will have rotted down before next year. Far better though to work out a way of discouraging your cats from using your veggie bed as a loo. They only use clean freshly dug soil so put something across it to deter them.

My Mum had problems with cats in her garden and she used fresh orange and lemon peel, you just spread it in your veg patch, it did take a few goes before the cats finally stopped coming.
I also saw on a t.v. programme about using old tea bags sprayed with deep heat and that keeps them away too.

As Jimmytheone and seaburngirl told me , try planting some "coleus canina" plant or better known as scaredy cat . It has a very pungent smell. Look at picture of it on "mystery plant from Madeira" 18 August.

Remove the poo and rake over the area. Place sticks (Bamboo canes/Wooden Canes/Branches etc) over the area - physical barriers are the only thing that stops cats, everything else is a a waste of time and money.

Aaah they drive me mad. The cat in question is georgous, of course, but I have been known to shout about seedlings dug up. Now when i sow or plant a row I push in sticks about 20cm long all over the area and that stops them digging. Usually.
It also poos on the grass which is quite unpleasant so perhaps i'll try the orange peel or tea bag trick.

I always put netting over my seedlings, supported by and tied on to short canes, with stones on the edges where the net touches the ground. I had to do this last bit with the stones because my cat used to go UNDER the netting to poo!! You can also put old prunings from bushes over the ground, especially if they're very twiggy, otherwise the cat will just tiptoe between them to do his stuff!! Best of luck with your cat poo, Jan!! Annie