Targeted trials for fertiliser use

New trials aimed at assessing the potential of foliar application of fertilisers to reduce the carbon footprint of cereal and other crops are to be carried out across Scotland.

The Farming for a Better Climate soil regenerative group, which was supported by SAC Consulting, part of Scotland’s Rural College (SRUC), carried out preliminary on-farm trials in 2020.

Then, 100kg/ha nitrogen was applied to a range of arable crops, followed by several 5kg/ha applications of foliar nitrogen.

On the strength of their results, SAC Consulting has been awarded funding from the Mains of Loirston Charitable Trust to test the effectiveness of this approach in scaledup plot trials.

Professor of crop physiology at SRUC, Ian Bingham, who is leading the project, said foliar feeds aim to supply small amounts of nutrients in a targeted manner to potentially increase fertiliser use efficiency and tailor crop nutrition to growth within a season.

“It may also have the added benefit of reducing a farm’s carbon footprint by using less fertiliser,” he said.

This year the trials will take place at three sites across Scotland – one with spring barley and two with winter wheat.

“The design of the trials will allow us to quantify how much of the nitrogen supplied through the soil and leaf is captured by the crop and contributes to yield,” said Bingham.

He added that fertiliser uptake would be calculated by measuring the crops’ nitrogen content at harvest, to allow the efficiency of fertiliser use to be compared between different treatments.