Norfolk trials help growers prepare for future challenges

Political ambitions to reduce carbon were a key area likely to create future opportunities, particularly within the new Sustainable Farming Incentive, services leader Matt Ward said. It was therefore important growers started assessing existing assets to ensure they were well placed to take advantage of new schemes.

Mapping soils with TerraMap provided a good way of establishing a baseline level of soil carbon (active and organic), against which the impact of future management practices could be measured.

“When thinking about carbon opportunities we also need to think beyond carbon sequestration or carbon trading, as there are various ways reducing the carbon footprint can benefit farm businesses, such as with less intense cultivations or improving fertiliser efficiency.”

Effective rotation planning and variety choice were highlighted as important ways of managing many of the risks facing growers, and with this autumn’s drilling plans being made, the varieties trial provided an ideal opportunity to see how new and established wheats had performed in another tricky season.

Plots and the surrounding 17 ha field of KWS Extase were sown early on 19 September in an attempt to avoid a repeat of the previous autumn when heavy rain prevented much wheat drilling. Like many parts of the country, wheat therefore came under significant Septoria pressure during June and July, the farm’s agronomist Tom Rouse explained.

“We have seen some big differences between varieties in treated and untreated plots, which reinforces the benefits of having a diverse rotation and growing a range of varieties to help spread risk.”

KWS Kerrin was another that had performed well as a first or second wheat, with good scores for mildew and brown rust, although yellow rust was a weakness that had to be managed well.

He acknowledged yellow rust control was being complicated by the emergence of new races, which made LG Astronomer of interest as it was based on a three-way cross (between Britannia, Leeds and Cougar), which had potential to hold up better against evolving pathogens than other two-way crosses.

The variety blend trial was another way of trying to use genetics to mitigate disease risk. It featured a blend of four varieties, KWS Extase, KWS Siskin, Graham and RGT Saki, in equal proportions to see if disease incidence could be reduced and yield improved.

All plots will be taken to harvest and full results available at a grower meeting later this winter.

In the fungicide trial, a 7-10 day delay in treating plots (compared with the main field application) had made a huge difference to Septoria and rust incidence at the Harleston site, where the interval between T1 and T2 reached almost five weeks due to the weather, Mr Robinson said.

“Accurate timing is absolutely critical to get the best out of fungicides, but particularly so with the demise of chlorothalonil.”

Wet weather in May and June had ramped up Septoria pressure in many wheat crops, and clearly highlighted the importance of maintaining a strong spray programme and tight intervals throughout.

Disease pressure was greatest where growers had eased back on early sprays due to cold, dry weather and lack of disease earlier in the spring, however this meant those crops had little protection when rain came later and spray intervals were extended due to bad weather, he explained.

“You’ve always got to do something at the main timings as you never know how conditions can change. The T2 spray is where many manufacturers focus their products, but we often see good responses to better treatments earlier in the programme, so it is worth investing.”

Varieties with strong disease ratings (e.g. KWS Extase) may not give the same yield response to fungicides as those with weaker ratings, but Mr Robinson said there was still a worthwhile return in most seasons, so doing nothing was not an option, and could put genetic resistance under greater pressure to breakdown.

Pre-harvest was an ideal time to review what had and had not worked during the season and start planning next year’s strategy across the whole rotation. “A lot comes down to how we can balance the rewards of yield and quality with the need to manage risks, whether that’s disease, establishment or pests.”

With so many interlinked factors to consider within ICM, he said digital platforms such as Omnia, with its disease, lodging and BYDV risk assessment tools, rotation planner and other data analysis functions were extremely useful for helping growers and agronomists work together to prepare effective cropping strategies for individual fields and across the whole rotation.

Mr Spackman highlighted four key pillars of ICM to consider:

• Agronomic strategy: optimise rotation, use variety resistance, blends, undersowing, intercropping, beneficial insects
• Risk assessment: use forecasting/ warning systems, thresholds, decision support tools, imagery, data interpretation
• Cultural methods: optimise cultivation strategy, support/enhance natural enemies, use biological options, and systems approaches
• Crop protection: optimise product choice, employ anti-resistance strategies, accurate timing, evaluate treatment efficacy and return on investment.

Hutchinsons’s Rob Jewers highlighted the importance of improving fertiliser efficiency as a way of addressing economic and environmental pressures.

Nitrogen for example, accounted for around 30% of total variable costs in winter wheat and made up 83% of the crop’s carbon footprint, yet just 50-60% of applied granular ammonium nitrate typically made it into crops.

The situation was even more significant for phosphate, where crop uptake for granular fertiliser was typically just 10% of the total applied, given its propensity to getting locked up in the soil.

“Improving fertiliser efficiency is therefore important for managing costs, but can also make a big difference to our carbon footprint.”

Tips for maximising Nitrogen Use Efficiency (NUE):

• Get fertiliser spreaders tested before the start of every year to ensure accurate calibration
• Select fertiliser products carefully according to crop and conditions (e.g. volatilisation losses from urea are greater in dry conditions, while granular fertilisers also need moisture to be taken up, so foliar applications may be more effective in some situations)
• Measure soil nitrogen with deep core testing in winter/early spring to check N carryover
• Use in-season testing (e.g. Yara N-Tester, or Omnia satellite imagery) to assess biomass and crop requirements
• Calculate NUE from final crop yields and application records
• Ensure all other nutrients are in balance, particularly phosphate and sulphur
• Check soil pH and lime if necessary.