AgSense has some of the best pivot control systems available; we use their AquaTrac connected to soil moisture sensors; the AgSense app keeps you informed
The new EnviroMonitor system by Davis Instruments is great when you need weather or soil moisture from many different parts of your farm
Campbell Scientific has meteorological equipment around the world and on the north and south poles; rugged, accurate and durable
Sentek is an Australian company that is considered by many to be the originator of the multi-level capacitance probe; they manufacture an easy to install tapered probe called the Drill & Drop that we use often
Meter Group (formerly Decagon Devices) makes a variety of capacitance and tension based sensors; we like the GS 3 in particular for nursery and greenhouse applications
AquaCheck makes multi-level profile probes that are durable, responsive and precise; we use this probe with many different crops and all types of irrigation
Irrometer has manufactured one of the most popular tension based soil moisture sensors ever; we have been using the "Watermark" for 30 years and it still gets the job done