How Strategic Cereal Farms tackle nutrient use efficiency

Nutrient use efficiency (NUE) is a large and complex subject, even when focused on one major nutrient – nitrogen. How nitrogen behaves in farming systems is often variable and hard to pin down, which is why it is a major discussion point at our Strategic Cereal Farms.

In this blog, Joe Martlew, AHDB Senior Knowledge Transfer Manager, provides a flavour of the fascinating programme of work across the network that aims to help farmers get to grips with nitrogen.

During November 2023, four Tuesday webinars highlighted the latest Strategic Cereal Farm results. This blog is based on the last of these webinars (which is available on YouTube).

The webinar was kicked off on a positive note by plant and soil health expert Joel Williams.

He said that at the heart of NUE is the aim to provide nitrogen in more readily metabolisable forms to plants.

Joel stated that this can be achieved in many ways, which he believes is a strength, not a weakness.

The range of options provides flexibility, giving everyone something to work with to meet the specific needs of their cropping systems.

Fiona Burnett (SRUC) and David Aglen (Strategic Cereal Farm Scotland host) gave an update on their tailored-input experiments, which investigate nitrogen (including foliar nitrogen) and crop protection.

Now in its fourth season, the experiments are generating a strong evidence base to understand nitrogen use at the farm.

Despite significant seasonal variation in NUE, a tailored approach to foliar nitrogen (in response to crop demand) has improved NUE and yield. However, the team feels that more evidence is required to unlock equivalent success with reduced crop protection (without compromising disease control).

In 2023, early grazing with sheep was trialled for the first time, but the team did not record any significant impact on NUE or yield. Overall, it has been a steep learning curve with some big lessons, including the need to use crop assessments that are easy to carry out and match key crop-growth timings.

Elizabeth Stockdale (NIAB) and David Miller (Strategic Cereal Farm South host) reflected on work that examines the effect of crop establishment approach on soil and crop health.

David explained his journey over the past decade, which has seen his farm move from conventional establishment systems with high cultivation intensity to ones associated with a much lower management intensity.

In addition to reduced cultivations, he also builds in diversity and flexibility in the rotation, which includes cover crops. By investing in soil systems and supporting beneficial organisms, he has also reduced reliance on inputs.

His on-farm establishment experiments test the potential of biological inputs to help cereals get off to an even stronger start.

However, despite being conducted over three seasons, no differences in establishment, yield or grain quality have been recorded.

The result may reflect, in part, the great health of David’s soils. With the soil strong, biological supplements struggle to add value.

Elizabeth highlighted that the biological inputs tested may deliver crop establishment benefits in suboptimal soils.

The team will now focus on a new trial to assess the impact of companion cropping in cereals.

Kate Smith (ADAS) and David Blacker (Strategic Cereal Farm North host) outlined results from a drainage experiment.

David is often challenged by his clay loams, which are extremely prone to extensive periods of waterlogging and have a history of associated crop failures. It is a top priority to fix.

Last year, drainage was installed across one of his fields (at various widths), providing a perfect opportunity to assess the impact on soils and crops, as well as the economic return.

In the first year, the team assessed the soil and crops to create baselines for monitoring. In general, the field has moderate-to-poor topsoil and subsoil health.

After the first season, the areas with new drainage provided a significantly higher winter bean yield (about a 0.5 t/ha uplift) compared to the old drains. This was supported by higher NDVI in the new drainage areas.

Rough economic estimates suggest that it will take about nine to 12 years to payback the investment in drainage, based on yield alone.

However, Kate stated it was important to account for all potential benefits, such as better NUE (reducing fertiliser requirements), fewer failed crops and better field access.

With more intensive sampling planned to better understand all impacts, this is a project to watch.

• Use simple measures to understand how nitrogen use efficiency varies on your farm
• Making general improvements to soil health may be better than pinning hopes on biological supplements
• Improving drainage in problematic fields can quickly boost yields (even in the first season)

Unleash the power of biodiveristy and unlock hidden potential within your business with Joel Williams.