N-Photo analysis

How to use the photo analysis?

The N-photo analysis tool analyses images taken with the phone's own camera and uses these to estimate crop nitrogen uptake. 

This works by taking several photographs looking down vertically on the crop these are then analysed to determine the leaf area cover and from this nitrogen uptake of the crop is determined.

To begin simply select or add the field in Atfarm app on your smartphone and identify the field as either oilseed rape or cereals, then scroll down and select photo analysis.

When used in oilseed rape Atfarm app photo analysis tool calculates a precise nitrogen fertiliser recommendation based on geolocation and growth stage. 

When used in cereals Atfarm app photo analysis 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 crops does Atfarm photo analysis work in?

N-photo analysis can currently be used in oilseed rape, winter wheat and winter barley.  

Oilseed Rape

When used in oilseed rape N-photo analysis 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 N-photo analysis tool 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. 

Cereals

N-photo analysis 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 N-photo analysis 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.