Lime on hay ground

I have the opportunity to get lime. First question, The lime is from milling bridge decks and interstates. Have you ever heard of this? Is it safe to use? They tell me that's all they use if for. Also he said I should use double the rate due to the neutralizing power. (Attached tests). So if it's fine to use what should my rate be? I'm in central Mn so can't get soil samples untill spring. The ground has never been limed that I know of (15+ years). I'm thinking around 2 ton to the acre on my orchard tymothy mix and 4 ton on my Teff ground because I can disk it in. I'm open to opinions and ideas. Thanks in advance.

Lime on hay ground