OptRx® Crop Sensors

OptRx Crop Sensors measure and record data about crops in real time using the reflectance of light shined on the growing plants.

The Optimum Prescription

Meeting your crop sensing needs.


The use of crop sensing technology in grains, cereals and other production ag crops is one technique to increase plant health and yield potential. OptRx Crop Sensors measure the needs of your crop and provide application rate recommendations for agrochemicals in real time to maximize your profit. 

The OptRx Difference

What makes OptRx crop sensors stand out from the competition?

  • Virtual reference strip. Unlike many other crop sensors on the market, the OptRx Crop Sensor doesn’t require a nitrogen-rich strip for making nitrogen application recommendations. Instead, OptRx relies on a new technology called a virtual reference strip. Growers simply identify the healthiest area of the field and scan that area in real time, rather than applying excess nitrogen to an area of the field pre-season and mapping that point.
  • User-friendliness. The OptRx sensor offers a user interface that exceeds previous sensors. OptRx directly interfaces with the InCommand® 1200 display to show the sensor readings and mapping onscreen along with other application data, such as rate control and automatic swath control.
  • Red-edge light wave. OptRx uses a red-edge light wave to scan plants. Most competitive products use only a red wavelength, which has been shown in studies to be non-responsive at high plant density. The red-edge lightwave stays responsive to health-stress on plants at later growth stages than other competitive products.
  • Single algorithm. OptRx crop sensors use a single algorithm application. Trials have been conducted in multiple states that have shown positive results of using a single algorithm in comparison to multiple algorithms.

How OptRx Works

OptRx Crop Sensors measure and record data about crops in real time using the reflectance of light shined on the growing plants. Sensors can be installed across the application boom to collect information while driving through the field. The data is logged and mapped to be used in further analysis – or for real-time variable rate applications. This kind of data is the key to precision farming. Collect information in the fields, analyze and then make decisions based on the data.

The OptRx crop sensor helps growers apply agrochemicals based on crop vigor. For example, the sensor tells the applicator to apply less nitrogen on healthy corn plants and more nitrogen on weaker, unhealthy corn plants, according to a calibration specific to that field.

In addition, OptRx’s advanced light-sensing technology is not dependent on ambient light – offering maximum flexibility to be used day or night.

What OptRx Can Do For You

  • Reduce application of nitrogen in nitrogen-rich areas.
  • Increase yield potential in nitrogen-poor areas of the field. 
  • Record crop vigor variation data across the field. 
  • Balance the effects of organic material variability across the field.
  • Improve yield potential for crops harmed by denitrification due to poor drainage.

When we variable rate spread based on the reading from the OptRx, we are able to put the nitrogen where it needs to be. - Eric Godwin, Prime Meridian, MO

Causes of Nitrogen Variability

Organic Material 

Organic material is one of the most significant sources of nitrogen in the soil. The more organic matter present, the more nitrogen the soil produces. Because organic matter concetrations differ across soil types, nitrogen availability in the soil can vary greatly throughout a field. 


Denitrification occurs as a result of poor drainage and uneven moisture distribution across the field. In standing water, nitrogen in the soil changes into a gas and is lost to the air, leaving soil in some areas of the field nitrogen deficient. Denitrification can cause a loss of five percent of nitrogen per day, causing significant variation across the field. 

Helpful Cutting Edge Tools

Vegetation Index (VI)

Using built-in intelligence, OptRx assigns a "crop vigor" number or Vegetation Index (VI) value based on plant biomass and nitrogen content. The VI evaluates the quality and variation across the field.

Calculating Nitrogen Rate

To determine nitrogen rate, OptRx must first identify the VI value that represents a plant with sufficient nitrogen available; this is called the VI Reference Value. To determine a VI Reference Value, users must drive the applicator over the healthiest looking plants for a minimum of five minutes. This process calibrates OptRx crop sensors for the given growth stage.

Rate Table 

OptRx crop sensors are ideal for applying fertilizers, pesticides, defoliants, growth regulators and other agrochemicals on-the-go at the rates necessary for optimum performance. Working with an agronomist or crop consultant, select a Vegetation Index range and assign the recommended rates based on the range chosen.

Downloads & Resources

Find a Dealer