There are no other effects at all? You mean, no impact on the volume of production, on prices?
Effect on volume of production? Not really, as people who are inclined to farm don't take most subsidies. Of course, the subsidies do drive up land prices, so those farmers may in fact put more of their land into production. Farming production is a very flexible figure and market forces remain market forces.
If "x" production occurs to meet "y" prices, then paying some people to reduce production would logically increase price, but that would result in other people producing more until the price falls back to "y". At this point, nothing has been accomplished, but a waste of tax dollars.
Let's assume that Joe's Muffler Shop doesn't do brakes, and you pay 50% of the brake shops in his area to stop doing brakes in order to increase the rate that can be charged for brake jobs. If you are successful in raising those rates, then you are going to see guys like Joe jumping into the brake job business and that will drive the prices right back down. But now you will be paying heavy subsidies to maintain the new status quo.