The rules for applying autumn nitrogen in the Nitrate Vulnerable Zone closed period in Scotland to winter barley could be simplified, according to the SAC’s Alex Sinclair.
In some situations there had been economic responses to autumn N, particularly on light sandy soils, although in most cases applications were not economic, he said.
To make applications during the closed period growers had to demonstrate a crop requirement, he noted.
“But defining the crop requirement is well nigh impossible because of variations in the weather and seed-bed conditions, for example.”
So to simplify the system he proposed that growers be allowed to apply autumn N based on the Macauley Institute’s indicative texture soil map.
Where growers were farming on sands, sandy loams and shallow topsoils applications would be allowed, providing slurry had not been applied, and the barley followed another white crop, he said.
“This does not mean every light land situation will give an economic response to nitrogen.
But the strategy should at least cover the most at-risk crops.”
The proposal had been given to SEERAD, he said.
“I am confident it views the idea as a workable option, but it is the European Commission that needs to be persuaded.”