A very short tutorial. Removing the photographer's shadow from the ground.
This is the image to be edited - take out the shadow.
In Quick Mask roughly paint around the shadow - going beyond the shadow edges a bit is necessary.
Next come out of Quick Mask, and Copy and Paste a new shadow layer (Layer 1 here). Then reload the selection (Reselect), invert the selection (Inverse), target the Background Layer and Copy and Paste a new layer to be used as a source for the Match Colour Adjustment (Layer 2 here).
I would suggest that in other cases where you would want to change/match the shadow colour to only a section of the Background then select that area of the Background, and copy and paste that area only. The above method works here because in this case the Background is mostly grass anyway, additionally the new layers can be made rapidly with keyboard shortcuts.
Next, targeting the shadow layer, open the Image/Adjustments/Match Color dialog and select the relevant Source and Layer. Immediately here I got a near perfect match - the light outline is where the selection goes over the edge of the shadow.
Last step is to add a Layer Mask and paint out the light outline.
Flatten the image, some minor Clone Tool work and you're finished. This was really quick and effective.