Increasing fertiliser prices and the ambition to achieve net zero have focussed attention on the importance of good nutrient management – particularly Nitrogen fertiliser Use Efficiency – and its financial and environmental benefits.
But what does good nutrient management look like? Today, a range of tools and strategies are available to help farmers reach that goal. ADAS hosted an Agri-Tech Week event to discuss recent developments.
“One good starting point is to measure what is in the soil”, said Dr Mechteld Blake-Kalff of Hill Court Farm Research. Her analytical lab has been helping farmers with measuring soil nitrogen supply (SNS), including additionally available nitrogen (AAN).
Measuring available nitrogen gives a better idea of how much nitrogen will become available from mineralisation during the growing season, having this information has been shown to improve Nitrogen fertiliser Use Efficiency (NfUE).
“By accounting for AAN in nitrogen recommendations, it’s possible to use less fertiliser and make some savings, while still achieving similar yields” commented Dr Blake-Kalff.
Working with Kellogg’s to benchmark Nitrogen fertiliser Use Efficiency
NfUE is also a variable that Clive Blacker, from Map of Ag, has been working on in collaboration with global food giant Kellogg’s and the EFFP, an agri-food consultancy. Together, they are encouraging their network of farmers to benchmark NfUE in order to determine their optimum fertiliser rate of application.
They have found that, intensive but regular data capture from crops (with the N Tester from Yara) throughout the season, combined with other environmental data sources, have provided real insight with tangible results. “This approach resulted in one instance in £53/ha of savings, representing a 20% improvement compared to standard on-farm practice,” said Clive.
Timing makes a difference
In addition to using technology and different data sources, different application timings can also make a difference.
A ‘Little and Often” (L&O) approach to application has been tested across different sites and years by ADAS researcher Kate Storer. “Drip feeding nitrogen throughout the season was shown to significantly increase N fertiliser uptake efficiency at two of the four sites tested, under added sugar application” revealed Kate. “Overall the L&O approach did not impact yield negatively”.
Another way to improve nitrogen use efficiency is to look at different ways of applying it. “People tend to opt for liquid application of fertiliser over solid because of its accuracy” commented David Booty from Omex Agriculture. Other advantages include the ability to incorporate nitrogen inhibitors to reduce run-off and phosphate protection, particularly in high pH soils.
Ultimately, deciding how much nitrogen to apply does come down to pricing. “How much one should buy is an economic decision” commented Daniel Kindred from ADAS. This is because the economic optima sits at the ‘Break-Even Ratio’, the quantity of grain that is required to cover the costs of 1 kg of nitrogen fertiliser. “With increasing prices, we are moving to a situation where not applying enough is costing us more”.
Finally, Daniel concluded that “we should be using a range of tools and experimenting on-farm” in order to decide how much nitrogen to apply in a particular situation. Forming part of initiatives like the YEN where there are opportunities to experiment and discuss results with peers is a crucial part of this.
This event was hosted by ADAS.
Agri-Tech Week features a mix of in-person and virtual events that are designed to showcase exciting developments in agri-tech. It is coordinated by Agri-TechE working closely with partners across the innovation ecosystem and aims to provide opportunities to attract new customers and partners and to broker collaborations and international connections.