Came out here for work. Part of UCDavis, this outdoor research facility is a working 300-acre ranch which monitors a range of agricultural practices like cover cropping, drip tape irrigation, etc. Parceled out in neat rectangles, this allows to monitor and study soil science to see what is optimal for producing crops.
I didn't see any horses, alas, but the folks who work here are very passionate about their work and it is a great way to gain hands-on experience about sustainable farming. Soil is tested to see what results in better soil health: organic methods, conventional, etc. I am obviously not a scientist so forgive the butchering of terminology.
(We did an informal science experiment where soil samples were tested in water to see the rate of disintegration. I was gently reminded that we were observing "soil aggregates" dissolve and not "dirt clods" as I wrongly suggested. Ha ha.)
They do offer tours! Just check out their website at: http://asi.ucdavis.edu/programs/rr/about/directions-to-rr. read more