Databases of Agriculture Indexes and Full text articles:
EBSCOhost, Agricultural Periodicals from the Northeastern US, 1789-1879; Coverage list and dates available at: https://www.ebscohost.com/title-lists
EBSCOhost Agricultural Periodicals from the Southern, Midwestern, and Western US, 1800-1878; Coverage list and dates available at: https://www.ebscohost.com/title-lists
WorldCat Subject headings and results with Links:
Agriculture -- Bibliography of bibliographies -- Catalogs. >> 6
Agriculture -- United States -- Periodicals -- Bibliography. >> 109
Agriculture -- Periodicals -- Bibliography -- Periodicals. >> 1,105
Agriculture -- Periodicals -- Bibliography. >> 1,105
Reference Books:
Blanchard, J. Richard and Lois Farrell, editors, Guide to Sources for Agricultural and Biological Research, 1981; Online availability in Google Books, click here.
Sheehy, Guide to Reference Books, Agriculture section, Horticulture section, Botanical section, etc.