How to prepare for spring fertiliser applications to enhance nitrogen use efficiency

As spring approaches, it’s important to dedicate time to properly planning fertiliser applications to ensure soil nutrient requirements are met accurately.

With increasingly unpredictable weather patterns making planning challenging, applying nutrients at the right time and in the correct quantities is one factor you can influence.

How to make the most of your nitrogen applications with soil testing

To understand your soil and crop’s specific needs, begin by carrying out a comprehensive soil test to gauge current nutrient levels. Consider essential elements such as nitrogen, phosphorus, potassium, and trace minerals.

This step helps to craft a tailored fertiliser plan for your soil’s specific nutrient requirements, ensuring your crops receive the nutrients needed for strong early growth.

To learn more about the soil testing tools available to UK farmers, read our recent blog.

Why do I need to test my soil?

Without information gained from soil testing, it’s impossible to make accurate decisions on inputs, risking over- or under-applying nutrients. This often leads to inefficient use of nutrients and potential harm to the crop and the environment.

Nitrogen deficiency can lead to reduced plant growth, fewer tillers, and smaller grain size, ultimately resulting in lower yields. Over-application can cause leaching – when soluble nutrients are washed out of the root zone by heavy rainfall, leaving crops with reduced nutrient stores and compromising yields.

To learn more about the importance of soil testing, read our recent blog.

How to choose the right fertiliser for your crop

For winter cereals and early-sown spring crops, nutrient availability early in the season determines how well plants recover from winter stress and establish strong root systems.

Each crop has unique nutrient demands in spring, and getting your fertiliser strategy right can significantly impact yield and quality.

Here’s how to optimise applications for your specific crop:

Winter wheat and barley:

Winter wheat and barley emerge from dormancy in early spring, making timely nitrogen applications crucial for promoting tiller survival and canopy growth.

Make sure to tailor nitrogen rates to tiller counts to match demands – over-application of nitrogen can cause lodging, where the plant becomes top-heavy and is unable to support itself, whereas under-application can lead to reduced yields.

Split applications can help weaker crops recover from winter stress, with later applications supporting stem extension and grain fill.

Sulphur is essential for nitrogen metabolism and protein formation, potassium improves water-use efficiency and straw strength, reducing lodging risk, while phosphorus enhances rooting and early-season energy transfer.

To learn more about the importance of sulphur applications, check out our recent blog.

Spring barley and oats:

Unlike winter-sown cereals, spring barley and oats have a short vegetative window before transitioning to reproductive growth. This makes early nutrition availability at sowing time critical, with a particular demand for nitrogen at this stage.

Sulphur should be applied alongside nitrogen to improve grain protein content and enhance nitrogen use efficiency (NUE).

With spring barley often grown for malting, careful nitrogen management is needed to balance yield with quality specifications, avoiding excessive grain protein levels.

Oilseed rape:

Oilseed rape also has a high nitrogen demand in spring, with early applications driving canopy expansion and crop resilience.

The AHDB RB209 nutrient management guide states that a well-established crop generally requires 50-75% of its total nitrogen by the stem extension phase, ensuring sufficient leaf area to maximise light interception.

Micronutrients, particularly boron, also play an important role in flowering and pod set, ensuring good seed development.

Maize:

Maize has a particularly high demand for phosphorus during establishment to support rapid root development and early growth.

Potassium plays a key role in water regulation and drought tolerance, improving plant resilience during dry periods later in the season.

Sulphur should also be considered to support NUE and optimise chlorophyll production.

Grassland:

For grazing and silage systems, spring nitrogen applications are essential for stimulating early growth and maximising fodder production.

The first application should be made as soon as growth begins, with rates adjusted based on soil type, sward condition, and first cut timings.

Sulphur is increasingly recognised as a key nutrient in grassland systems, improving nitrogen uptake as well as boosting protein content.

Potassium plays a key role in maintaining sward density and root health too, particularly in multi-cut systems.

Where phosphorus levels are low, spring applications can help drive root development and improve early-season growth, particularly in reseeded or newly established grasslands.

For a more detailed look at how to optimise grassland quality, check out our blog.

When to apply spring fertiliser to crops

Applying fertilisers in unsuitable conditions can lead to significant nutrient losses and cause harm to the surrounding environment.

Here are some pointers for achieving the most successful spring fertiliser application:

• Avoid spreading during heavy rainfall or on waterlogged soils, as these conditions increase the risk of runoff into watercourses.
• Wait until hard frosts have passed and temperatures are consistently around 10 degrees Celsius to ensure the soil can absorb the nutrients effectively.
• Apply fertilisers when soils are dry but not compacted – nutrients and water struggle to travel through compacted soil, making it difficult for them to reach the root zone, resulting in significantly reduced nutrient availability and wastage.