N-Tester
Free
The N-Tester® works by optically measuring the chlorophyll content of leaves, which is strongly correlated with the plant's state of nitrogen nutrition. Thirty measurements repeated several times in the plot will give a representative average for the plot, and will help determine whether or not the crop requires additional inputs. The N-Tester® value is strongly influenced by growth stage and variety. Climatic conditions and crop biomass also influence the index measured.
Access the tool
Name in original language | N-Tester |
Name in English | N-Tester |
Designer/ manufacturer | YARA - ARVALIS |
Accessibility | Free |
Weblink | https://www.yara.fr/fertilisation/outils-et-services/n-tester/ |
Countries of primary use | France, Germany, United Kingdom |
Main language | French |
Other languages available | English, German |
Brief description of the tool | The N-Tester® works by optically measuring the chlorophyll content of leaves, which is strongly correlated with the plant's state of nitrogen nutrition. Thirty measurements repeated several times in the plot will give a representative average for the plot, and will help determine whether or not the crop requires additional inputs. The N-Tester® value is strongly influenced by growth stage and variety. Climatic conditions and crop biomass also influence the index measured. |
Target user | Tool/product manufacturer |
Target crops | Barley, Wheat |
Type of tool | Crop analysis |
The tool assesses or provides guidance on | SPAD, Leaf nutrient content |
Nutrients assessed | Nitrogen (N) |
Nutrients assessed in the lab | Not included |
The tool relies on a base recommendation system | Yes |
Base recommendation system | Balance sheet forecasting method for N, in accordance with the equations defined by the COMIFER. |
The assessment frequency should be | Once per week during set growth stages |
Required data input is | Crop, Variety, Farm location, Nutrient input, Growth stage |
The data can be imported from other tools and systems | No |
The tools main output format is | PDF file |
Data can be exported | No |