I don't know the history of this cactus. Neighboring cacti appear to be healthy, but this one is covered with lesions. Any ideas on what they are?

New to the forum and cacti in general. Recently purchased a property with a large collection. How large? Let's just say a few acres. Trying to learn everything I can about these plants. I'll be back now and then with questions, for now here are a few pictures. Currently in bloom bloom001.jpg Partial...