How new technology can help boost nitrogen use efficiency

• Improvement essential for future

• Managing in-field emissions is key

• Technology promises lots to offer

Innovative thinking and technology is helping growers optimise profits and while making their businesses more sustainability by improve nitrogen use efficiency (NUE).

Use of inorganic nitrogen fertilisers is usually the single largest component of the carbon footprint of crop production and any attempt to decarbonise food production must address this, says Peter Scott, technical director of Origin Fertilisers.

“In a typical combinable crop, 50% of the carbon footprint is related to the production of the fertiliser in the first place and the other 50% is due to in-field emissions,” he explains

“But, around half of human dietary protein consumed globally is directly related to the use of inorganic nitrogen and in the west, this would be much more. The issue of nitrogen use goes to the very heart of sustainable food production.

“Low-carbon nitrogen, made from green or blue ammonia, could play an important role in the future with regard to reducing the carbon footprint of manufacture, but we must also address in-field emissions.”

Going local

The pH of soil together with its organic matter content and structure plus other considerations such as drainage all impact on emissions, so better management is essential in the future, he points out.

“One of the biggest things we can do, and one of the most important benchmarks for delivering future sustainability full stop, is to focus on nitrogen use efficiency (NUE). The higher the NUE, the lower the nitrogen loss, but you have to measure it to manage it.

“NUE changes from season to season, field to field and crop by crop, so it is no good using default average values or national levels. We need to get local and we all need to encourage growers to do this.

“Once we know what the NUE is at farm level, only then can we take appropriate steps to reduce emissions.”

Farms manager Peter Cartwright, of Lincolnshire’s 2400ha Revesby Estate, says focusing on NUE has been essential in monitoring their own use of nitrogen and allowed better understanding of how technology can be used to improve it.

“Nitrogen use is definitely a main element of our carbon footprint, but we’re finding there are ways of managing it more effectively.

“Our own trials have shown the benefits of using Agri-Start Liquisafe, a nitrification inhibitor which holds nitrogen in the soil, for example, with some trials pointing to a 50% reduction in yield without the technology.

“We’re also getting good results from using biologicals in the early stages of crop growth to promote plant health and build green area and this can help reduce the need for nitrogen.

“Rotation is important, too. We include peas and beans wherever possible to put nitrogen back in the soil and improve it’s all overall health plus cover crops are increasingly being used.

“Aiming to produce high yield is an often overlooked element of reducing the carbon footprint of crops. A 10t/ha yield dilutes the carbon footprint per tonne produced considerably, compared to a lower one.”

New technology

Agrii technology trials manager Jonathan Trotter believes emerging technology will make a vital contribution to improving NUE and delivering sustainability, with Revesby Estate one of the company’s first digital technology farms (DTF) to be up and running.

“The idea behind DTF is to understand how we can leverage and integrate different technologies to make decisions on-farm and see how they can enhance decision making compared to a traditional agronomic approach.

“So, for example, the Skippy Scout drone system can monitor above ground crop growth and information from this could be enhanced by data on below ground nitrogen levels from in-situ soil nitrogen sensors such as Plentysense nitrogen blades.

“These sense nitrogen availability at three different levels in the soil – 10, 20 and 40cm – and there is a telemetry head that sits on top of them that tells us in real time what N the soil has.

“We can then understand how the nitrogen is moving through the soil profile to help improve decision making around nitrogen management.

“This data can be combined with that from Soiltech Wireless soil moisture and temperature sensors dug into the ground, for example, and all the information we are collecting can link to Agrii’s Rhiza online Contour platform.

“We are also starting to use hyperlocal disease prediction models based on key risk factors and data.”