Yes a rowing machine can help you lose belly fat but you must use the rowing machine around 30 to 40 minutes each day and use the rowing machine everyday if you want to lose a significant amount of belly fat.
Using a Rowing Machine for around 30 minutes per day burns around 300 calories which means that you can shed some of that belly fat overtime.
It might take 6 months to a year to see a good loss of belly fat but it will eventually work if you stick too it and you should also watch your calorie intake and do other exercises such as walking, jogging etc.
Apple Cider Vinegar can also help you lose belly fat along with using the Rowing Machine.