Oats – too much nitrogen will reduce crop quality

Ongoing Teagasc research has been designed to identify those crop management practices that will deliver optimal yield and crop quality, where the growing of oats is concerned.

The work is seeking to identify all of the components of crop yield in tandem with those factors that impact on crop growth and grain quality.

Sara Tudor, the person coordinating this research work, spoke at the recent Teagasc National Tillage Conference. She said:

Oats are the third most popular crop grown in Ireland and the UK with both consumption and the area grown on the rise.

According to Tudor, approximately 210,000ha of oats are now grown in the UK. The equivalent figure for Ireland is 23,800ha, split 70% winter crop and 30% spring.

She continued:

“Output of oats in Ireland now amounts to 203,000t annually. The current Teagasc research programme is looking at a range of factors that impact on the profitability of growing oats, including: nitrogen input; environmental variation; varietal choice; and identifying the ways by which yield and quality can be optimised.

Producing oats to meet milling specification is key.

Nutrient guidelines

Tudor went on to confirm that current nutrient guidelines for oats do not reflect the full impact of added nitrogen.

“Current trials are looking at the impact of applied nitrogen on both winter and spring varieties. The work will also assess the impact of nitrogen, genotype, location and year on yield components and milling quality.”

Identifying the optimal nitrogen application rate for oats is a key priority in the context of the ongoing Teagasc research. Work carried out to date confirms that the figure is variety dependent. It will also be dependent on the growing conditions that unfold each year.

“Calculating the economic optimum nitrogen level, necessary to achieve high yield with the lowest input cost will maximise grower profits,” said Tudor.

Nitrogen application

The Teagasc figures available for 2019 confirm that the optimum nitrogen application level for the spring oat variety Canyon was 174.9kg/ha; the equivalent figure for the variety Conway was 118kg/ha.

According to Tudor, too much nitrogen can affect grain quality.

“A high yield of oats does not mean that the crop will have a correspondingly high quality value,” she said.

For example, specific weights decline as more nitrogen is applied. Millers want oats with a specific weight of 52kg/hl or above.

“In addition, Teagacs trials carried out in 2019, covering both winter and spring oat varieties, show that screenings increase as nitrogen fertiliser levels rise.

“Kernel content and hullability are more impacted by varietal difference than nitrogen application levels,” Tudor concluded.