What Is Ag Tech? Practical On-Farm Sensing, Monitoring, and Moisture Testing Tools

Ag tech, in practical farming terms, is the electronics and sensors mounted on or used alongside farm equipment to measure what is happening in the field and act on it. The main categories are monitors, controllers, ground speed sensors, and moisture testers. You need basic monitoring if you only want to see what your machine is doing; you need a control system if you want the equipment to adjust itself automatically. Moisture testing is a separate, bench- or cart-based job tied to harvest and grain marketing decisions.

The four tool categories that make up most on-farm ag tech

DICKEY-john, which has been building agricultural electronics for over 50 years, groups its product line around monitors, controllers, moisture testers, and ground speed sensors. That grouping is a useful way to think about the category as a whole.

The distinction that matters most to a buyer is monitor versus controller. A monitor tells you something. A controller changes something. Everything else in ag tech tends to be a variation on those two roles.

Monitors: seeing what the machine is doing

A monitor is the entry point. It takes signals from sensors — a shaft turning, a fan spinning, seed dropping — and puts a number or an alarm in front of the operator. The value is early warning: a plugged row, a slipping belt, or a fan that has stopped shows up on the display instead of in a yield map at the end of the season.

Choose monitoring first if your problem is that you don't know what's happening. If you already know the problem and just need the machine to fix it, skip to controllers.

Controllers: closing the loop

A controller uses the same sensor inputs but drives an output — a hydraulic valve, a metering roll, a conveyor — to hold a target rate or population. This is where ag tech stops being a dashboard and starts being automation.

The practical condition for a controller is that you have a target you want held automatically across changing conditions: varying ground speed, varying product density, varying terrain. If your application rate is already consistent because your conditions are consistent, a controller buys you less.

Ground speed sensors: the input everything else depends on

Ground speed is the quiet dependency in most rate control. Radar and other ground-speed sensors measure how fast the machine is actually moving over the ground, rather than how fast the wheels are turning. On soft or sloping ground those two numbers diverge, and any rate calculated from wheel speed will be wrong by the same amount.

If you are troubleshooting inconsistent application rates, check the speed source before you replace the controller.

Moisture testers: the harvest and marketing tool

Moisture testing is a different job from in-field monitoring. A grain moisture tester — DICKEY-john's line includes the GAC family of grain moisture testers — measures the moisture content of a sample so you can decide whether to harvest, dry, blend, or sell.

This is the category where the decision is financial as much as operational. Moisture content affects storage risk and the price you receive, so the tester needs to match the grain you actually grow and the range of moisture you actually see. When comparing testers, compare them on the same dimensions:

• Grain types and calibrations supported — does it cover your crops?
• Moisture range — does it read the wet end you see at harvest, not just dry grain?
• Sample handling — how much grain per test, and how long per test?
• Where it lives — bench unit, cart-mounted, or portable to the field?
• Repeatability — do repeated tests on the same sample agree?

How sensing data feeds planting, application, and harvest decisions

The categories connect in a chain rather than standing alone:

1. Planting. Population and seed spacing sensors feed a monitor; a controller holds population as speed changes. Ground speed is the reference input.
2. Application. Flow and pressure sensors feed the monitor; the controller adjusts valves to hold rate. Again, ground speed sets the target.
3. Harvest. Machine monitoring covers the combine's own functions, while moisture testing happens on the grain itself — either in the field or at the bin.

The practical takeaway: if you improve only one link, improve the speed and sensing inputs first. Controllers cannot correct for a bad measurement.

Basic monitoring or a full control system?

Use these conditions to decide:

Start with monitoring if:

• You don't currently have visibility into machine performance
• Your application rates are already acceptable and you mainly want alarms and records
• You are adding technology to older equipment incrementally

Move to control if:

• Rates or populations drift with speed or terrain
• You are applying expensive inputs where over- and under-application both cost money
• You want the operator to focus on the field rather than on manual adjustments

Add moisture testing regardless if:

• You make harvest timing, drying, or selling decisions on grain
• You need a number you can act on rather than an estimate

Most operations end up with a mix: monitoring on some machines, control on the ones where rate accuracy pays, and a moisture tester at the point where grain changes hands or goes into storage.

Where to go next

If you are specifying equipment, work backward from the decision you want to improve — rate accuracy, machine uptime, or grain moisture — and identify which of the four categories owns that decision. DICKEY-john's product line is organized along exactly those lines, so its monitors, controllers, ground speed sensors, and moisture testers are a reasonable reference set for comparing what each category does before you commit to a system.