Original database (sr25.mdb/MS Access) was downloaded from: https://www.ars.usda.gov/Services/docs.htm?docid=22771
Then it was converted using mdbtools and script from: https://github.com/elcio/mdb2mysql
Converted file had every row in separate INSERT. After 24h of loading data to database, I dumped it using mysqldump. Difference is that on my 6-7 years old TOSHIBA notebook, I can DROP,CREATE&INSERT same data in less than 5 minutes.
After loading data to database, columns had different lengths than they were in documentation so I changed them appropriately.
Compressed using: tar czf sr25.tar.gz sr25.sql Uncompress using: tar -xzvf sr25.tar.gz
After uncompressing sr25.sql size is about 61MB.
Version with added relations is under 'relations' branch.