Trimble GreenSeeker Handheld Crop Sensor for Farmers

Shri Subhash Pattnaik, Regional Sales Manager -(Agriculture), SAARC Region of the Trimble Navigation India Private Limited informed about the latest developments and the Green Seeker in a Media Round Table Meeting wherein Shri Rajan Aiyer, Managing Director, Trimble spoke on the Precision Agriculture in India.

Shri Pattnaik also informed about Trimble’s GreenSeeker and narrated the interaction with Moga farmers of Punjab regarding the product and how it helps farmers detect nitrogen deficiency in the soil.

He also spoke to Krishi Jagran Team in Hindi for the benefit of Farmers of Northern area and in Odia for the benefit of Odisha Farmers. Interested people can visit the Krishi Jagran Main Facebook Page and Krishi Jagran Odia Page for more updates. 

The GreenSeeker handheld crop sensor is an active light source optical sensor that is used to measure plant biomass and display as NDVI (Normalized Difference Vegetation Index). When you pull the trigger, the measured NDVI reading appears on the LCD display immediately. 

The sensor works upon pulling the trigger, the sensor turns on and emits brief bursts of red and infrared light, and then measures the amount of each that is reflected back. While the trigger remains engaged, the sensor continues to sample the scanned area by generating continuous bursts of light pulses and updating the display. 

Green plants absorb most of the red light and reflect most of the infrared light. The relative strength of the detected light is a direct indicator of the density of the foliage in the sensor’s view. The denser and more vigorous the plant, the greater the difference is between the reflected light signals. The sensor displays the measured value on its LCD.  

NDVI can range from 0.00 to 0.99. A LCD display B Battery access panel C Wrist strap attachment loop D Trigger E microUSB port for charging F Remote switch connection G String attachment loop. 

Using the Sensor -  Hold the sensor over the crop canopy and then pull the trigger. The sensor should be held 24 - 48” above the crop. Observe the reading on the display. The sensor’s field of view is an oval; its size increases with the height of the sensor (approximately 10” wide at 24” above the ground, 20” wide at 48” above the ground). 

To obtain a reading representing a larger area, walk with the sensor while keeping the trigger engaged and maintain a consistent height above the target. The display updates continuously, but accumulates multiple readings and provides an average when the trigger is released. The maximum measurement interval is 60 seconds. f You must pull the trigger to start a new measurement. The unit automatically turns off after completing the measurement. You can pull the trigger to clear the screen and begin a new measurement at any time. Typical applications for using this tool include sensing and agronomic research, biomass measurements and plant canopy variations, nutrient response, yield potential, pest and disease impact. This allows you to get real-time readings for grain crops, vegetables, turf, sugar cane, and many others. 

Using the sensor to estimate a fertilizer rate A key use of this sensor is to estimate fertilizer application rates. Sensor measurements combined with agronomic information such as type of crop, may be used to estimate a fertilizer rate. The steps that follow show one procedure to get readings for a field that includes a reference area. These values are then referenced on the chart and table to determine a rate per the example. The current algorithm is available as a separate document (Fertilizer Estimation Chart). 

An N-Rich strip is a small area within the field to which more than enough fertilizer has been applied at or before planting. This area will be a gauge of the crop not limited in vigor due to insufficient fertilizer. Including a reference area or “N-rich strip” provides an accurate method to determine how much additional fertilizer is necessary to maximize the crop yield in a particular field.  

Use the peak value within the N-rich strip and a value typical of other areas of the field as two inputs to the Fertilizer Estimation Chart to determine an application rate. 

For more information on the N-rich strip practice, go to www.trimble.com/agriculture/greenseeker.