Salmon | Flickr
Louisiana Drones | Flickr (USDA)
Cow Ultrasound Michigan State University | Flickr (USDA)
IoT Device Connection | Flickr (USDA)
Kansas State Cow Ear Tags | Flickr
Precision Agriculture Frick Farms | Flickr (USDA)
Technology
Wisconsin NRCS | Flickr
US Department of State Photo Archive | Flickr
Kentucky and Tennessee Land Between the Lakes KY/TN | Flickr
FNS-Farm to School at Royalton-Hartland SD in Niagara County, New York | Flickr (USDA)
California kqedquest | Flickr
Not strictly ag, also air/space pics, land management, etc.
Indiana Tom Britt | Flickr
PA Good Harvest Farm Blossoms from Energy Savings | Flickr (USDA)
Pics of using energy, water
Nonlethal Methods for Wildlife Damage Management | Flickr (USDA)
Good land-management, etc. pics
New York NRCS | Flickr
New Mexico NRCS | Flickr
Oregon NRCS | Flickr
Montana NRCS | Flickr
Scotland – Food, Feed, and Crops | Flickr
Stock photos of food (for human consumption), feed (for animal consumption) and agricultural crops.
Massachusetts – Terry Donovan | Flickr
Massachusetts – Chickens, Terry Donovan | Flickr
Texas NRCS | Flickr
Georgia – UGA CAES/Extension | Flickr
College of Agriculture and Environmental Sciences, Georgia
Missouri – MUExtension417 Extension | Flickr
Carol M. Highsmith's America | Flickr
Also on Rawpixel.
Montana – Beaverhead-Deerlodge National Forest | Flickr (USDA)
Timber logging forestry wood.
Agriculture Research Service (ARS) | Flickr
Oregon Department of Agriculture | Flickr
Pennsylvania Department of Agriculture | Flickr
Lumber, forestry, wood.
Washington State Department of Agriculture | Flickr