The Greenseeker Handheld sensor is manufactured by N-Tech Industries and sold by Trimble. The sensor on the handheld unit and variable rate units are the same.
Development of the Handheld "Pocket" Sensor
The Pocket Sensor was developed to produce the same NDVI reading as a GreenSeeker just in a small more affordable package.
The GreenSeeker™ technology provides an opportunity for the producer to apply only the needed N fertilizer on their farms, thereby maximizing their production and reducing their cost of production.
Use the GreenSeeker handheld to instantly take a reading of your crop’s health. Readings can be used to make non-subjective decisions regarding the amount of fertilizer to be applied to your crop, resulting in more efficient use of fertilizer.
GreenSeeker Sensor Flat Rate
Utilizing Reference Strips and the GreenSeeker Sensor for full field N rate recommendations is a common approach utilized in winter wheat production throughout OK.
Timing of Sensing
There is an optimum time at which the N-Rich Strip should be sensed with the GreenSeeker Sensor.
- For Winter Wheat, this is after green up in the Spring and before hollow stem. Typically 90-110 GGD's are needed.
- For Winter Canola, the timing is before winter dormancy or just prior to bolting in the spring.
- For Corn and Sorghum that is between 6 and 10 leaf stage, prior to tassel or head emergence.
GreenSeeker Sensor Variable Rate
Variable Rate Nitrogen Application has been evaluated by Oklahoma State Researchers since 2000.
"The GreenSeeker RT200 real time integrated optical sensing and application system measures crop status and variably applies the crop's nitrogen requirements. It predicts yield potential for the crop using the agronomic vegetative index NDVI. The nitrogen recommendation is based on in-season yield potential and the responsiveness of the crop to additional nitrogen.
Numerous NDVI readings are averaged across each zone. A prescription is written. The controller modifies the rate for each ensuing zone. The RT200 works with most variable rate controllers and delivery systems. The sensors can be mounted on booms of various configurations on most sprayers/spreaders. The RT200 allows application of UAN, UREA and NH3 fertilizers. The retrofit is quick and easy." N-Tech Industries RT-200 VRT applicator web page.