Parsnips do fork if you transplant them but they can also fork when grown direct into the ground.
They are still all right to peel, cook and eat, at least you are getting parsnips which can be hard to germinate.
Put them into the ground as soon as they show using the loo tube. This way you control where they get planted as well as getting a result. It is not actually transplanting, they stay planted where they were started you just give them more growing space.
Too much richness can make them fork too.
I think that the farmers must grow them directly into compost because we can now get some used parsnip and carrot compost delivered to the allotment because the grower uses fresh stuff every year.
No wonder they cost so much in the shops. Fresh compost, scrubbed, manicured and wrapped in plastic.
