The Yara N-Sensor Index is what sets Atfarm apart. It has been developed using Yara's expertise in precision fertilization, based on more than 25 years of research and over 250 field trials conducted with the Yara N-Sensor.

The Yara N-Sensor is a tractor-mounted remote sensing device that determines crop nitrogen demand by measuring light reflectance. Since the 1990s, it has been used in cereals to optimize fertilization strategies.

Using crop- and region-specific calibrations, Atfarm generates optimized biomass maps that detect variability in crop development even at advanced growth stages. This is particularly important for late nitrogen applications.

How does it compare to NDVI?

Most other tools rely on the Normalized Difference Vegetation Index (NDVI), which has significant limitations.

Limitations of NDVI

• Not crop-specific: NDVI provides a relative value between zero and one, indicating only the presence or absence of green biomass. It doesn't account for specific crop types or growth stages, limiting its applicability in tailored fertilization strategies.
• Saturates quickly: NDVI measures red and near-infrared radiation. In dense crop canopies, NDVI reaches saturation, meaning it can no longer differentiate biomass levels. This makes it unreliable for mid-to-late growth stages.
• Limited to early growth stages: Due to its quick saturation, NDVI is useful only for planning the first nitrogen application and is ineffective for later stages of crop development.

Why is the Yara N-Sensor Index more accurate?

Unlike NDVI, the Yara N-Sensor Index can detect biomass differences during and after shooting. This is because it measures not only red and near-infrared radiation but also the spectral ranges in between. With this fine gradation and the inclusion of crop and regional data, the N-uptake can be accurately estimated, even in advanced growth stages where NDVI is no longer effective.

Advantages of the Yara N-Sensor Index

• Less sensitivity to canopy saturation: Unlike NDVI, the Yara N-Sensor Index remains effective even at BBCH 50-60, depending on the crop.
• More precise nitrogen uptake estimation: By incorporating additional spectral data and crop- and region-specific calibrations, Atfarm's biomass maps provide more reliable nitrogen recommendations throughout the season.
• Optimized for multiple fertilizer applications: Atfarm's biomass maps help you plan second, third, and protein dressings with Variable N-Rate Application maps, ensuring nitrogen is applied precisely where it's needed.

How Atfarm's biomass maps help decision-making

Atfarm's optimized biomass maps help you:

• Apply nitrogen more precisely throughout the season, beyond early growth stages.
• Create Variable N-Rate Application maps based on crop-specific biomass data.
• Detect biomass variations even in later growth stages, improving fertilizer efficiency.
• Avoid over- or under-fertilization, ensuring crops receive the right amount of nitrogen.

With Atfarm, you can plan your fertilizer strategy more effectively and make data-driven decisions throughout the growing season.