Spring Decisions: Timing, Nutrition, Results

Precision Nitrogen for Spring Crops: Improving Fertiliser Efficiency

Nitrogen remains one of the most valuable inputs on any arable farm. With fertiliser prices rising and increasing pressure to improve nutrient use efficiency, growers are looking more closely at how and when nutrition is applied.

Applying nitrogen with greater precision can improve crop uptake, reduce losses and help protect margins. It also helps ensure fertiliser is used where it delivers the greatest return.

In this episode of the Tramlines podcast, Agrii specialists discuss how precision nutrition, liquid fertiliser and digital tools can help growers improve fertiliser efficiency and crop performance.

Where this was discussed in the episode

If you’d prefer to listen to the relevant sections, these points are covered in the podcast at:

• 00:00 – Why precision nutrition matters
  Nitrogen costs, rising pressure on efficiency and why precision matters more than ever.
• 01:45 – How efficiently crops use nitrogen
  Typical nitrogen use efficiency on farm and where improvements can be made.
• 03:40 – Using satellite imagery and field data
  How digital tools can help guide fertiliser decisions.
• 06:20 – Liquid fertiliser and application accuracy
  Why liquid systems can improve application precision.
• 07:10 – Nitrogen inhibitors and crop response
  Trial results showing improved nitrogen efficiency and yield.
• 15:05 – Using weather data to improve timing
  How hyper-local weather information helps plan applications.
  
  

Why is precision important when applying nitrogen?

Nitrogen is a valuable input, but crops rarely use all of what is applied.

In many situations, crops may only utilise around 60% of applied nitrogen, with the remainder lost through leaching, volatilisation or other pathways.

Historically, fertiliser was often applied at a single rate across the entire field. However, most fields contain considerable variation in soil type, crop development and yield potential.

Precision application helps address this by:

• matching nitrogen supply to crop demand
• targeting areas of higher yield potential
• reducing unnecessary fertiliser use
• improving overall nitrogen use efficiency

Even relatively small improvements in nitrogen efficiency can make a significant difference to farm margins.

How efficient is nitrogen use on most farms?

Nitrogen use efficiency varies widely between farms and seasons.

Where variable rate nitrogen strategies are used, more of the fertiliser applied is captured by the crop rather than being lost from the system.

Improving nitrogen efficiency is therefore one of the most practical ways to increase the return from fertiliser investment.

How can satellite imagery guide fertiliser decisions?

Satellite imagery is now widely used to identify variation in crop biomass across fields.

These images highlight areas where crops are growing differently. However, interpreting them correctly is important.

Areas showing lower biomass on vegetation maps do not necessarily represent crop failure. In many cases they indicate areas with lower yield potential rather than no crop at all.

Satellite imagery should always be combined with field inspection and agronomic assessment to understand the reason for variation.

Once this variation is understood, nitrogen rates can be adjusted to better match crop potential across the field.

Should nitrogen be applied to weaker areas of the field?

A common question with variable rate nitrogen is whether fertiliser should be directed towards weaker crop areas or stronger areas.

There is no universal answer.

The key factor is yield potential.

• Strong crop areas may justify additional nitrogen to maximise yield
• Moderate areas may benefit from balanced applications
• Very poor areas may not justify full nitrogen rates

The aim is to apply fertiliser where it is most likely to deliver a return in yield.

What advantages does liquid fertiliser offer?

Liquid fertiliser systems can provide several practical advantages when precision application is required.

Compared with solid fertiliser, liquid systems can deliver:

• more even distribution across the boom width
• improved accuracy for variable rate applications
• consistent coverage across headlands and irregular fields
• faster crop response in dry conditions

Liquid fertiliser also contains three forms of nitrogen, allowing both immediate and longer-lasting nutrient availability.

In seasons where soils are dry, liquid fertiliser may move into the soil more quickly than granular products, helping crops access nutrients sooner.

Can nitrogen inhibitors improve fertiliser performance?

Nitrogen stabilisers or inhibitors can help protect fertiliser from losses after application.

These products slow the processes that convert nitrogen into forms more easily lost from the soil.

By keeping nitrogen available for longer, crops have more time to absorb it.

Where conditions favour nitrogen losses, stabilisers can help improve nitrogen use efficiency and crop uptake.

How contractors support precision fertiliser applications

Contract sprayers are increasingly equipped with technology that supports precision fertiliser application.

Many contractor machines already include:

• GPS guidance systems
• variable rate application capability
• mapping software for field data

For farms without this equipment, working with a contractor can provide access to precision application technology without additional machinery investment.

Contract services can also help ensure fertiliser applications are completed during short weather windows in busy spring periods.

How weather data improves fertiliser timing

Weather conditions have a significant influence on fertiliser performance.

Rainfall, soil moisture and temperature all affect how quickly nitrogen becomes available to the crop.

Digital platforms can now provide hyper-local weather data, combining information from nearby weather stations, radar systems and digital sensors.

Because weather patterns can vary significantly across relatively small distances, this information helps growers and contractors identify the best time and location for fertiliser applications.

What Agrii trials are showing

Work across Agrii’s Digital Technology Farm network is helping to demonstrate how precision nutrition strategies perform under real farm conditions.

Trials running across sites from Scotland through Lincolnshire to Essex are exploring how variable rate nitrogen and digital crop monitoring can improve fertiliser efficiency and crop performance.

Results so far show that taking a more targeted approach to nitrogen applications can significantly improve how efficiently crops use applied fertiliser.

Across these trials, nitrogen use efficiency improvements of up to 15% have been recorded when variable rate nitrogen strategies are used, helping a greater proportion of applied fertiliser contribute directly to crop growth.

Alongside this work, replicated trials have also explored the role of nitrogen stabilisers in protecting applied fertiliser. Across 42 winter wheat trials, the addition of a nitrogen stabiliser alongside liquid fertiliser applications delivered an average yield increase of around 4%.

These findings highlight the value of combining several elements of a precision nutrition strategy:

• understanding crop variability within fields
• applying nitrogen more accurately across that variation
• protecting applied nitrogen from losses
• using digital tools to guide application timing and rates

Taken together, these approaches help ensure more of the nitrogen applied ends up in the crop rather than being lost from the system.

Practical takeaways for growers

If you want to improve nitrogen performance this spring, focus on a few practical steps.

• Understand variation within fields before adjusting fertiliser rates
• Use satellite imagery alongside field walking to guide decisions
• Consider variable rate nitrogen where crop variability is significant
• Protect applied nitrogen where losses are likely
• Focus on improving nitrogen efficiency rather than simply increasing fertiliser rates
  
  

Summary

Improving nitrogen efficiency is becoming increasingly important for both farm profitability and environmental performance.

By combining accurate application, digital tools and careful timing, growers can ensure more of the fertiliser applied contributes directly to crop growth.

For many farms, the next step is not applying more nitrogen, but applying it more precisely and making better use of the nitrogen already being applied.