Lessons from Strategic Cereal Farm East (harvest 2024)

Harvest 2024 marked the end of the first year of our Strategic Cereal Farm in Norfolk. Henny Lowth reflects on the findings of the farm’s three research areas: cultural weed control, BYDV management and nutrient use efficiency (NUE).

Last year, host farmer David Jones and our research partners (NIAB, ADAS and Harper Adams University) carefully crafted a set of trials that tackled some of the biggest challenges at Strategic Cereal Farm East.

Last month (14 November 2024), I went to a meeting with over 40 farmers and other stakeholders, who were all eager to hear how the first-year trials had fared.

David faces significant grass-weed pressures on his farm, especially Italian rye-grass, but he is determined to use less herbicide.

NIAB’s Jack Poulden explained how a field strip trial is examining how to stack chemical and cultural (mechanical) weed control options to produce the best of both worlds.

One of the biggest challenges for any trial is when the control target refuses to play ball. Unexpectedly, the trial field had hardly any weeds. Additionally, the weather made in-field operations extremely difficult (at best) or impossible (at worst). In the end, we were forced to test the mechanical weed control options in other fields.

The main barrier to the inter-row hoe treatment was confining damage to just the inter-row space (not extending it to the spring barley crop). We planned a second pass in the spring, but fast crop growth stopped us. Frustratingly, where the first pass stimulated weed growth, it caused an even bigger headache.

We also used a weed surfer to take off weed seed heads. This demonstrated useful control levels, especially when the timing hit the sweet spot (good numbers of heads removed above the crop canopy).

Of course, weeds are adaptable. Long-term use could select for shorter grass weeds and reduce the impact of weed surfing. We discussed other machines that could help minimise seed return (for instance, the Zurn top-cut and collect was cited).

To help assess treatment impact, weed seedbank data is being collected. We are taking soil samples from various depths and germinating the weed seeds in a polytunnel (see picture below).

Although this unearthed about 12,000 seeds per m2, we only recorded an average of 18 weed plants/m2.

David Jones said:

“Grass-weed herbicides are under enormous pressure, which can lead to resistance and poor performance.

"This work package explores the use of mechanical weed control, alongside herbicide control, to drive down the rye-grass population in the weed seedbank.”

David was interested in reducing insecticide use long before the no-insecticide option appeared in Sustainable Farming Incentive (SFI), which offers £45/ha.

ADAS’ Duncan Coston’s trials aim to improve approaches for aphid/BYDV management in winter wheat.

The trial is split across two winter wheat fields: the first planted with a BYDV-resistant variety (RAGT Grouse) and the second planted with a BYDV-susceptible variety (KWS Dawsum).

The initial plan also included the use of decision support tools (T-sum and Acrobat*) to guide insecticide timings, with results compared to an untreated control.

Once again, the weather scuppered the plans and prevented insecticide applications across the trial. The dismal autumn weather also reduced aphid numbers, which probably would have reduced the quality of the results anyway.

With crop condition also poor, it made identifying BYDV symptoms even more challenging than usual. In fact, the presence or absence of aphids and potential symptoms often failed to match up with the detection of BYDV in tissue samples.

Testing for viruses (including for the various BYDV strains and other cereal viruses) is also a highly technical process, adding further complexity.

David Jones said:

“Insecticides are often considered a cheap and easy way to tackle BYDV. However, spraying causes other problems, especially insecticide resistance in aphids and the reduction in non-target species.

"This work aims to reduce our reliance on insecticides by using decision support tools, good varietal selection and the SFI incentive payment of £45/ha.”

NIAB’s David Clarke is examining NUE to help the farm reduce mineral-based fertiliser inputs.

He used a computer model (called Sirius) to predict the NUE associated with each nitrogen application timing on the farm. The tradition soil nitrogen application at the final split delivered the lowest NUE by far (47%).

In response, a NUE trial was set up to test whether a foliar, controlled-release nitrogen application (MZ28) could do a better job at the final split.

The trial featured three treatments:

1. All nitrogen applied to the soil.
2. Final soil dose replaced with foliar nitrogen.
3. Untreated (no nitrogen control) at the final split.

When all nitrogen was applied to the soil, yield increased by 0.3 t/ha compared to the untreated control. The relatively wet season may have improved its uptake. However, no yield increase was observed in the foliar treatment (compared to the untreated control).

A second NUE trial tested variable rate technology in fields with known variation, based on historic soil and yield data available from a longer-term SAMS trial.

At the three sites, three nitrogen rates were applied in three large plots. The optimum nitrogen application at each of the three sites varied significantly, highlighting the potential for a variable-rate approach.

However, it also emphasised the need to vary nitrogen in response to field potential, rather than uniformity.

David Jones said:

"With the cost of nitrogen fertiliser skyrocketing in recent years, there has never been a better time to find cost-effective improvements.

"The use of foliar methylated urea has been heralded as an alternative to less-efficient, soil-applied nitrogen. This work will explore the credibility of such claims.”

Nitrogen use efficiency plots in winter wheat

• Not everything can be controlled (such as the weather and pest pressures), and this challenges the ability to generate scientifically robust data
• However, as such challenges reflect commercial pressures, it demonstrates the value of hosting research on commercial farms
• Having a farm with a well-rooted history of conducting research avoided the need to start from scratch: in terms of the experience of the on-farm team, connections with researchers and the established network of local, engaged farmers

Full harvest 2024 results will be published early next year.

*We anticipate that the new BYDV tool (Acrobat) will be released by the end of 2025.

ADAS is asking farmers in the local area to get involved in a peer-to-peer learning platform called the BYDV IPM hub (as part of IPM-NET).