Soil biology issues muddy climate fight

Abasic lack of understanding of soil biology, especially among policy makers and politicians, is confusing the climate change debate, according to Eric Anderson, senior agronomist with Scottish Agronomy.

Speaking at a BASF potato trials day at East Nevay in Strathmore, he explained that sequestering carbon in soils, thereby increasing organic matter content, was seen as being beneficial in a simplistic way but not enough attention was being paid to the interaction between the carbon cycle and the nitrogen cycle.

“As we increase organic matter in the soil, so we increase biological activity and thus the release of nitrous oxide. This is 298 times as damaging as carbon dioxide in terms of causing climate change,” he said.

“This means we have to be cautious but there are things we can do. For example, saturated soils release much more nitrous oxide. Better drainage and a return of drainage grants would be a help.”

Applied nitrogen, of course, had a major role to play. If crop productivity can be increased with the same or fewer inputs than previously, then the farm’s “carbon footprint” would be reduced.

One way to achieve this would be to use a urease inhibitor such as BASF’s Limus Clear. At a cost of £2 to £4 per hectare, this was economically viable and considerably reduced the emissions of unutilised ammonia.

Mr Anderson said: “The use of a urease inhibitor would be particularly useful under certain environmental conditions such as periods of low rainfall, drying soils or warm soil temperatures. All of these increase the risk of ammonia losses.

“For example, using Limus Clear in the third nitrogen application in winter cereals in April would be appropriate.”

Limus Clear can be tank mixed at 0.2 litres per hectare in liquid nitrogen fertilisers at the time of application or an alternative Limus product can be blended into a granular fertiliser at the point of manufacture.

BASF’s Paul Goddard explained that the company was increasing its focus on the potato crop and had several new products due for release over the next two or three years.

The East Nevay trials included plots of a new herbicide, BASF 65612, which had been designed to work best in conjunction with partner chemicals.

“We had individual stars in the past but now it is very much a team approach with some quite complex tank mixes,” Mr Goddard said.

A new systemic product, named Honesty, is also being trialled. Likely to be launched in 2023, it targets rhizoctonia and can be applied to the tuber at grading or in-furrow at planting.

EMISSIONS: Eric Anderson of Scottish Agronomy backed the use of a urease inhibitor.