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.
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| 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 |