I am looking to purchase 50 acres of land and put a house on it (~$700,000 total). Can I get a loan for this without 20% down?

Maybe, but not likely. Construction loans are viewed as high risk loans, and have tighter restrictions. Next, there is no central clearing house for constructions like, like a Fannie Mae or Freddie Mac. You need to contact each lender to ask. You may get lucky, but less than 20% down is not the norm, especially since COVID. Learn more at https://joemetzler.com/new-construction-loans/ - I lend in MN WI IA SD ND. Cambria Mortgage, NMLS 274132