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 | 
 
         
         
         
         
         
         
         
         
        