My name is jessie and two months ago I allowed my one year old to stay with his father after we split because I was doing farmwork and did not have a reliable babysitter. Nor did I know what days and times I would be working. I have primary custodianship of our son and his father has not constantly paid support or helped me with our son. I was still seeing my son on a weekly basis, sometimes for days at a time or even a solid week. When I told his father I was keeping my son in my possession because his environment was not a healthy or stable one he has now filed abandonment charges on me and today had a judge give his an emergency temporary custody of him. Not to mention he lied and said that I abducted my son from my mother who was babysitting my son on halloween. Which didn't happen. We both took the child trick-or-treating together and then he left him with me. Does he have a case?

Somewhat.
I don't think he can get you for abandonment if you say you had an agreement for him to watch your son while you were away working trying to support him. BUT he can probably win on saying you can not provide a stable environment for your son because of unusual hours. His motive for what he is pulling may be trying to win custody so he can go after you for support. It is important you try to be reasonable with him and try to work a reasonable workable agreement for joint custody. As long as you are going after him as unfit he will fight back with lies and exaggerations.

The best thing you can do is find a job with more suitable hours and show the Judge you have arrangements (with your mom or whoever) when you are working before you have to go to court.

If he tries to use abandonment as his reason for changing custody, he will be refused. However, the instability of your situation could change matters. On the other hand, if you can show he committed perjury, that's not going to make the judge look kindly on him.