YaraIrix - Turn your phone into a nitrogen sensor

YaraIrix is a smartphone app that allows you to measure the nitrogen demands of your crops at a different growth stages.

Combine the accessibility of smartphone technology with Yara's deep agronomical knowledge. YaraIrix puts a powerful crop analyser in your hands. To use it, download the YaraIrix app (iOS and Android) and begin taking photos of your crops

What does YaraIrix do?

The YaraIrix app analyses images taken with the phone's own camera and uses these to estimate crop nitrogen uptake. 

Used in oilseed rape YaraIrix calculates a precise nitrogen fertiliser recommendation based on geolocation and growth stage. 

Used in cereals YaraIrix will give an estimate of crop nitrogen uptake which can help an experienced agronomist give a more accurate nitrogen recommendation. 

This basic image analysis based estimation is only valid at early growth stages in the spring and has only been calibrated up to GS 31 in cereals and stem extension in oilseed rape.


What else does YaraIrix do? 

As well as the image analysis YaraIrix can be used in conjunction with the Yara N-Tester to determine the nitrogen status of cereals at later growth stages, up to anthesis. With this extra information about the plants nitrogen status, the optimum amount of nitrogen can be calculated to fine tune final N applications. The recommendations given are for yield only. Apply an extra 40 kgN/ha where good milling quality is the target. The N-Tester can be used to monitor the crops Nitrogen status right through to anthesis as a decision support tool.

YaraIrix will already work with older models of the N-Tester but in development there are now two additional hardware options – N-Tester Clip and N-Tester BT – that open up precision farming technology to both large and small-scale farmers for the very first time.

What crops does YaraIrix work in?

YaraIrix can currently be used in oilseed rape, winter wheat and winter barley.  

Oilseed Rape

When used in oilseed rape YaraIrix will determine the crop biomass and nitrogen uptake and based on this will give a nitrogen recommendation.

Yara’s nitrogen trials have shown the strong relationship in oilseed rape between canopy size in early spring and the optimum rate of nitrogen required. As the canopy of oilseed crops can vary greatly between different fields due to differences in drilling date, soil types, topography and slug pressure, amongst others, the optimum rates can vary greatly also. To take a canopy fresh weight measurement to assess nitrogen uptake in each field can be very time consuming, and an average across all fields may not show the true variance within. 

The YaraIrix app helps to speed up measurements by quickly providing a value for nitrogen uptake in the crop and a recommendation of the rate to apply, based on a minimum of four images per field. Eight years of data capture over very different seasons has led to over 12,000 crop images, each with a corresponding laboratory analysis result. This has enabled a wide range of different nitrogen rates, seed rates, drilling dates and measurement dates to be analysed to create a robust tool and provide confidence in the result. 


YaraIrix can also be used in winter wheat, winter barley, winter oats and winter rye too.

When used in winter wheat or winter barley prior to stem extension YaraIrix will determine the crop nitrogen uptake but not give a recommendation, however the crop nitrogen uptake can then be used in conjunction with other measurements to fine tune nitrogen recommendations and can be used as an aid to crop management. 

When used in conjunction with the Yara N-Tester  the YaraIrix app  will determine the nitrogen status of cereals at later growth stages, up to flag leaf and ear emergence.  With this extra information about the plants nutritional status of the plan the optimum nitrogen recommendation amount at ear emergence can be calculated allowing growers to fine tune final N applications.

I already have an N-Tester, will YaraIrix work with older versions of the N-Tester?

Yes absolutely - YaraIrix will support any model of the N-Tester.

All you need to do is to download the basic free version of YaraIrix app, then register the N-Tester within the app to let it know which model you have then you are good to go. Just take the N-Tester readings as normal and use the YaraIrix to convert the 'three digit reading' into a variety and growth stage specific nitrogen recomendation.

YaraIrix and N-sensor

What about newer versions of the N-Tester, when will these be available?

New for 2019 there are two exciting new N-Tester developments

The first hardware option is the N-Tester Clip. This is an add-on that 'clips' over a smartphone's camera to enable precise N recommendations.  At present this is only available for Android phones but the iPhone version should be available for 2020.

The second hardware option is the N-Tester BT, which works just like the older N-Testers but communicates with the YaraIrix app using Bluetooth.  This is still being tested as a pilot in 2019 with only very limited numbers available, more will be available in 2020.

How do I get started with YaraIrix?

Simply download YaraIrix for free for iOS or Android and then sign in to begin analysing your crops.

To use for image analysis at early growth stages just start taking photos within the app. After taking a photo, you’ll receive an instant N fertiliser recommendation that you can use to plan your first dressing. 

If you already have an N-Tester simply register this within the app to let it know which model you have, then you are good to go.

If you’d like to register for either the N-Tester Clip or N-Tester BT within YaraIrix or follow the links to the YaraIrix website.

Download YaraIrix now!


Get YaraIrix on Google play
App Store YaraIrix


The N-Tester variety recommendations are updated every year to include newer varieties as more calibration data becomes available.

Following the introduction of YaraIrix app the simplest way to obtain a variety specific nitrogen recommendation is to use the N-Tester inconjunction with the YaraIrix app.

All you need to do is to download the basic free version of YaraIrix app, then register the N-Tester within the app to let it know which model you have then you are good to go. Just take the N-Tester readings as normal and use the YaraIrix to convert the 'three digit reading' into a variety and growth stage specific nitrogen recomendation.

For more information see YaraIrix

Alternatively, if you would still like to download the varieties directly into your N-Tester (2013-2018 version only) then please download the N-Tester loader programme and use this update the new variety calibrations into the N-Tester.

There is no link between the N-Tester reading and the level of nitrogen (Nufol) to apply for protein. The N-Tester is aimed at providing a recommendation for final nitrogen applications to achieve optimum yield.

What the N-Tester will do with continued monitoring is tell you how much nitrogen the crop is able to pick up and will help identify what is happening in the plant. The most important starting point for achieving milling protein spec is to get the nitrogen right for yield. Wheat crops remobilise nitrogen from the leaves to the grain during flowering, but this does not start until mid-flowering, therefore if, through weekly N-Tester reading, you identify levels of nitrogen in the plant falling prior to this time, it can help to identify shortages in nitrogen which will need to be rectified prior to applying the Nufol for protein. As this is likely to be beyond the GS45 cutoff, the absolute recommendation will not be relevant, however something would be beneficial to ensure the crop is optimally fed.

If the nitrogen levels continue to increase, or remain flat, then you can be more confident of optimal nitrogen rates, and therefore just go with the standard Nufol application at the standard timing.

The N-Tester measures the leaf chlorophyll content and uses this to determine the nitrogen content.  This is different from 'free nitrate' which is nitrogen that has been taken up by the plant and stored in the leaf but not yet incorporated into protein.

The most reliable method to determin free nitrate content is to conduct a leaf tissue analysis.

If you need to get in touch with the YaraIrix team directly:

Email: feedback@yarairix.com
Telephone: +44 1484 509725 (office hours only)