This is a Krupp commercial specimen. Large numbers were sold to Russia as the Model 1909 in calibre 122mm. Your photo illustrates the weapon with a different splinter shield than usually seen, but it is a factory pic.
Some hints in identifying WW1 artillery are usually found in the breech and wheels. German ordnance usually have 12 spoked wheels, while French normally have 14. If you see an artillery piece from this period with a sliding breech block it will likely be of German origin.
Exactly the same picture appears on p.21 of Jager's 'German Artillery of WW1' captioned as a Krupp 105mm howitzer, which I knew was wrong, but I hadn't a clue as to what it actually was. Thanks for clearing that up, 28juni14. And don't forget, sliding breechblocks could also be Austrian!
Actually this was one of the few 10.5cm commercial field howitzers manufactured pre-war by Krupp; to be precise it is a Krupp 10.5cm M-1912 or M-1912/16 field howitzer, a model sold to Romania to the tune of 60 examples; Bulgaria also had a quantity, some of which were captured from the Romanians; they seem also to have apparently taken delivery of some from Krupp directly after their entry into the war (the later M-1912/16?). This is the only photo of one of these rare howitzers commonly available that I know of (found in Herbert Jäger's book), or at least that I have so far seen. Its appearance matches the written descriptions I have of it (L/14 ordnance, size etc...).