Do I need to use captcha if I am using AntiForgeryToken in an MVC application?
A CAPTCHA is a type of challenge-response test used in computing to determine whether or not the user is human. (...) CAPTCHAs are used to prevent bots from using various types of computing services or collecting certain types of sensitive information. - Wikipedia
Cross-Site Request Forgery (CSRF) is a type of attack that occurs when a malicious Web site, email, blog, instant message, or program causes a user’s Web browser to perform an unwanted action on a trusted site for which the user is currently authenticated. - OWASP
As you've read, they are both completely different aspects of security. And both CAPTCHAs and CSRF prevention can be bad for the user experience if not implemented right (browser usability issues, hard to solve CAPTCHAs, etc).
With that being said, I think I've answered all your questions with this. I suggest you check out the sources I've linked to. It will eliminated most, if not, all (further) questions you might have regarding this topic.