This dredging will make Argentina and possibly some of Southern Brazil a higher reliability supplier, less problems with low water levels on dry years and larger ship capabilities deeper inland. With a more consistent and reliable ability to get to the heartland other expansions will come. These expansions will likely include livestock facilities and a loading port for the reefer intermodals. Barring a global weather cataclysm North America has lost the Chinese market. Should be good for the Argentinian and some Brazilian farmers, at least in the short term.
China will likely get the added bonus of a deepwater port for their navy in the western hemisphere when Argentina does an Argentina and defaults on the loans.