You can see what information was asked on the agricultural schedules at http://www.census.gov/history/pdf/agcensusschedules.pdf (The 1900 starts on page 12)

However, according to "The Source" the ag schedules for 1900 and 1910 were destroyed by Congressional order some time ago, apparently once statistics were gathered.

The 1880 agricultural schedules are available on microfilm for most states. I imagine the films are at the National Archives or its regional branches, http://www.archives.gov/locations/ or at the state level. Some states are online at Ancestry but MS does not appear to be (see http://search.ancestry.com/search/db.aspx?dbid=1276)