"Would I be able to put horse dung straight from field around hornbeam hedge and veg patch as it has no straw or hay to rot down?"
The short answer is no. Whilst it is important to add organic matter to your soil to improve the structure, manure needs to be at least a year old before being used. Until then it is too acidic and will scorch the plants, it will have weed seeds which have not been killed by the heat of the rotting process (this can be a problem even with rotted manure if the heap has not heated up enough) and finally it may pong a bit!
Mrs R would be better off starting a compost heap to mix the manure with other garden waste to get a good balance, and wait until it breaks down, when it will have a lovely friable texture, will smell like earth and be full of valuable nutrients - gardeners gold!
We will be covering soil, manures and mulches together with planting techniques on Tuesday February 2nd 2010 - see our courses page for details