Choosing the right fertiliser is not always straightforward. In addition to finding an option that suits your crop requirements and promotes robust growth, there are other issues to consider too. More and more farmers are seeking a fertiliser that can offer greater sustainability for their farm whilst delivering a reliable spread of nutrients to secure good yields.

There comes a point where applying more nitrogen starts to deliver diminishing returns and only harms the surrounding environment. One measure that is increasingly important in finding a sustainable balance between nitrogen application and environmental protection is nitrogen use efficiency (NUE). It measures the efficiency between the total nitrogen input compared to the nitrogen output, with a higher percentage being desirable for efficient nitrogen usage.

1. What’s the difference between blends and compounds?

Blends and compounds are both multi-nutrient products but are created differently. Blends are fertilisers made by mixing together different raw materials to a defined overall composition of specific nutrients. A compound instead mixes these ingredients earlier in the process to produce a granule or prill that contains every required nutrient and is therefore the exact same shape, size and density.

2. How is application different?

For a compound, application is simple. As the prills and granules are all uniform, a single spreader setting is required for consistent and accurate application.  For blends, it is a bit more complicated. As the fertiliser will contain granules or prills of different shapes, sizes and densities, any spreader setting will inevitably be, to some extent, a compromise. This often results in uneven application of nutrients across a field and therefore increased lodging and reduced crop quality and yields.

With increasing bout-widths, it becomes even harder to achieve an even spread with a blended fertiliser. The further you try to spread a blended fertiliser, the more disparity in nutrient landing sites you’ll see. Have you ever tried throwing a ping pong ball as far as a golf ball? It’s the same principal with differing particle densities.

Additionally, the new controlled traffic approach has led to maintaining the same tramlines in fields year-on-year. Whilst this makes sense in protecting your soil for future crop yields, it does mean that if you’re spreading a blended fertiliser you’ll suffer the same nutrient deficiencies in the same areas of your fields every year, so you will see a worsening in nutrient availability.

Switching to a compound fertiliser is an easy solution to avoid these risks. If you’re going to invest in a superior fertiliser spreader match it with a high quality fertiliser, otherwise, your investment is all for nothing.

3. What is the effect on Nitrogen Use Efficiency (NUE)?

In the quest for profitable crops, it’s important that we don’t discount the environmental impact of achieving such yields. A useful measure to adopt a balanced approach is Nitrogen Use Efficiency (NUE). There comes a point where applying more nitrogen to your crops becomes less effective to growth and more detrimental to the surrounding environment. Research has shown that by increasing NUE in arable fields will deliver plentiful yields with minimal cost to the environment.

4. Does NUE loss have a significant financial impact for my farm?

Achieving the a good NUE provides dual benefits of greater sustainability and an increased return on investment.

By using a blended fertiliser, tests have shown that you could suffer a yield loss of around 0.5 t/ha in a wheat crop. When you extrapolate that across an area of 100 hectares, using today’s wheat prices, that could represent a loss of as much as £9600. Using, a quality compound fertiliser will deliver a ROI of roughly 3:1- much higher than that of a blended fertiliser.  

At the same time, agriculture’s responsibilities in protecting the environment seem to increase every year. Retailers are making environmental commitments to consumers which are quickly getting passed down the line to farmers. Achieving a high NUE percentage is just one thing farmers can do to improve their overall sustainability.

5. How does sustainability compare beyond NUE?

To achieve true sustainability you need to see the whole picture when it comes to fertiliser – not just the immediate effects on farm. Greater control over the production of compound fertilisers have made it possible to reduce N2O emissions considerably. For example, Yara developed ‘abatement’ technology to remove over 90% of N2O emissions during the nitric acid production stage of manufacture.

To deliver on promises for sustainability, the transparency of the field to fork approach should go further to include considerations on fertiliser production. Clearly, not all fertilisers are created equal.

Conclusion

In summary, compound fertilisers are far more likely to enable farmers to achieve profitable crop yields whilst meeting sustainability commitments at the same time.

“The only way to ensure even distribution across the field – especially when spreading across ever-increasing bout widths – is to use a compound fertiliser,” says Natalie Wood, Country Arable Agronomist at Yara. “With compounds, wherever a granule or prill lands, you know the full complement of nutrients are there for the crops to take up and results in up to 10 times more landing sites, compared to a blend.”

For more information, visit www.yara.co.uk