It's hard to tell from the pic. if the bushing in the valve is threaded or slip. If it's threaded than the repair is real simple using a 1" male adaptor, a 1"x3/4" bushing and a flow-span repair coupler. If the bushing is glued in than the valve will probably need to be replaced.

OK, the solution is tricky to do the first time but you can handle it if your very careful and a bit lucky. Dig a hole away from the valve about 12-18" long and about 2"-3" deeper than the pipe. Exposing the pipe all around so you can cut it off. Cut off the pipe as close to the bushing as you can without cutting into the bushing. Cut carefully. Cut off the pipe a few inches past the break. When you have this done you will see the pipe inside the bushing. Take a hacksaw blade out of your hacksaw and carefully cut through the pipe BUT not into the bushing. Be very careful. Move over inside the pipe about 1/4" and make another cut. Take a hammer and a very thin flat screw driver and very carefully tap the screw driver between the pipe and the bushing. Go slow and DONT hit hard. Angle the screw driver slightly toward the middle of the pipe so your applying most of your tapping to the pipe and not the bushing.

If all goes well you will pop out a bit of the pipe in a grove 1/4" wide. Now carefully work the rest of the pipe out by tapping the screw driver between the pipe and the bushing working around the pipe. Often the pipe will pop out in one or 2 larger pieces. Be sure to get all small bits out.

Repair the pipe/bushing with a bit extra glue and primer and it should be as good as new. If at any point the bushing cracks/splits you will have to replace the whole valve.

Good luck,
Tom