Yara N-Tester™

N-Tester™ is a hand held tool which enables quick and easy measurements to be taken through a growing crop to establish its exact nitrogen requirement.

This enables fast and accurate field specific recommendations to help finetune application during the growing season. This can result in more accurate field scale recommendations, improving profitability and minimizing environmental effect.

Ask your Plant! 

The nutritional status of the plants determines the timing and amount of fertilizer. With the N-Tester™ it is possible to identify the nitrogen requirements of plants directly on the field easily, safely and quickly. The nitrogen fertilizer demand is never constant and can vary considerably from year to year and field to field.

By splitting the N-fertilization into more dressings, it is possible to optimize the N-fertilizer rate according to the actual plants needs on any field in any year.

A plant analysis with the N-Tester™ gives valuable information about the current nutritional status of the plant. In cereals from this measurement, the optimum N-fertilizer amount at the time of stem elongation and ear emergence can be calculated.

The use of N-Tester™ ensures your economic success

A series of field trials were carried out to assess the advantage of using N-Tester™ to fine tune nitrogen applications. Applying the correct level of nitrogen to a cereal crop can have a significant benefit both on yield and on grain quality. Ensuring the protein content of grain meets grain buyers specifications can have a significant impact on crop profitability. Trials have shown that by using N-Tester™ large increases in grain protein content can be achieved.

How does N-Tester™ work?

N-Tester™ operates by measuring the chlorophyll content of the leaf, as this is related to the Nitrogen status of the plant. The measurement point should be in the middle of the lamina of the youngest, fully developed leaf. Thirty random measurements from across the field, taken using the usual ‘W’ pattern, give an average value that is used to indicate how much Nitrogen the crop requires. Deriving a fertilizer recommendation is only possible if no other nutrient is limiting the crop growth.

The N-Tester™ measurements are strongly influenced by crop variety and growth stage. For this reason the N-Tester™ measurements must be calibrated to take account of this variation. Ask your local Yara agronomist to support you with calibration and to provide you the fertilizer recommendations based on the N-Tester™ measurement.

Trials in France

  • More than 240 field trials on cereals
  • Increased protein content of 0,3%
  • Increased yield of 120 kg/ha
  • Additional yield lead to an increased gross margin of more than 18 €/ha (cost of application deducted).
N tester

N-Tester™ performance compared with nitrogen applications following the Calculation of Balancing in France.