Features
U.K. update: All about carbon sequestration

Agriculture is often referred to by a number of buzzwords. The latest terms seem to be hanging around longer than normal: “carbon sequestration.”

There is now a huge drive for countries to become net-zero for carbon by a set range of timely targets.

For example, in 2019 the U.K. government became the first major economy to pass a net zero emissions law. This led to an ambitious target that requires the UK to bring all greenhouse gas emissions to net zero by 2050, and that means farmers need to add their weight to achieve that goal.

While carbon dioxide (CO₂) is essential for a healthy planet, too much of this greenhouse gas can cause havoc with the environment and lead to global warming. Carbon dioxide production stems from a number of sources in agriculture, industry, deforestation, burning fossil fuels and natural occurrences like volcano eruptions. As intensive farming and industrial activity ramps up, so too can the production of carbon dioxide.

When carbon and other heat-trapping emissions are released into the air, they act like a blanket, holding heat in the atmosphere therefore warming up the planet as a consequence.

Net-zero means that any carbon emissions created are balanced, or cancelled out, by taking the same amount out of the atmosphere. This means that countries could reach net-zero when the amount of carbon emissions produced is no more than the amount that is taken out of the atmosphere.

Farmers are only too aware that the climate is changing all too rapidly as droughts and floods, with exceptionally high or cold temperatures, wreak havoc with their farming calendars when it comes to producing food.

So what exactly can farmers do? Well, there are many ways carbon can be removed from the atmosphere, the most obvious of which is to plant trees that then absorb CO₂ and release oxygen.

That takes us to the globally fashionable term of “carbon sequestration.” It can be defined as the process of capturing and storing atmospheric carbon dioxide which reduces the content of the gas in the atmosphere, and at the same time helping mitigate the effects on the climate. Many experts and organisations have called for an increase of carbon sequestration practices across the world, as well as a reduction of the amount of CO₂ being released into the atmosphere in the first place.

Selling carbon credits
There is now a drive on for farmers to increase their carbon sequestration efforts while at the same time securing some extra income by selling carbon credits to big companies seeking to offset their emissions production, or carbon footprint as it is more widely known as.

If managed correctly, fields used for agricultural production can act as a carbon sink through sequestering greenhouse gasses such as carbon dioxide.

This means the carbon can be trapped in the soil and it stays there. However, some farm management practices such as ploughing or tilling can release the carbon back into the atmosphere again.

The buyers of carbon credits will pay a set amount for each carbon unit, or tonne of sequestered carbon, and prices can fluctuate depending on the demand.

Microsoft hit the headlines earlier this year when it purchased USD $500,000 worth of carbon credits from a large beef farmer in Australia. Wilmot Cattle Co successfully sold more than 40,000 tonnes of sequestered soil carbon to the tech giant, following the farm’s dedicated grazing management programme.

The farm has practiced time-controlled rotational grazing, increased stocking density and decreased paddock size for the last ten years which has led to greater ground cover, biomass and water-holding capacity on more than 4,000 hectares.

This management plan has boosted productivity and resulted in soil organic carbon concentration increasing from 2.5 to 4.5 per cent, moving closer to the farm’s goal of six per cent by 2023.

First carbon credit farmer
Back in 2014, Angus McIntosh, who practices regenerative farming in South Africa, was the first farmer in the world to sell carbon credits after increasing the carbon content in the soil of the pastures where his cattle, sheep and pigs graze and forage. Regenerative ag builds up the soil, resulting in healthier plants, which in turn feeds the animals from the pastures producing grass fed protein for human consumption.

Angus keeps up to 200 pigs on his farm and does not have fixed housing for them. The pigs are kept on the rougher land that is destined for reseeding and are moved to fresh ground at least once a week. He bases his system on the high density grazing methodology (“mob-grazing”) using the manure and urine that is deposited onto the soil to eliminate the need to apply artificial NPK fertilisers.

The pastures were established with a variety of perennial summer and winter legumes, herbs and grasses. Once an area has been grazed, the animals are moved giving the pasture and soil time to regenerate and fully recover. Six weeks passes before the pastures are grazed again.

The ultra-high stock densities result in large depositions of manure and urine, along with extensive trampling of the field. This trampling spreads the manure  over the field, disrupts the soil surface and tramples vegetative organic matter into the soil surface. Together these factors promote increased soil carbon levels, beneficial microbial activity and grass root health. Angus said: “Letting a group of foraging pigs loose [on] marginal land is an excellent method of regenerating the soil back into production and is a more environmentally friendly practice.”

He said the areas that the pigs have grazed had a 24 per cent higher carbon content compared to areas just metres away where they had not been scavenging. In fact, 7,101 tonnes of CO₂ has been sequestered on the farm since 2017 such is the success of Angus’s type of regenerative farming.

Reducing emissions
Efforts are currently underway on farms and in agricultural industries across the world to reduce the amount of CO₂ released in the atmosphere.

One of the largest animal feed manufacturers in Northern Ireland has already successfully reduced carbon emissions by 34 per cent after switching energy supply.Based in Omagh, Fane Valley’s Bankmore Mill converted its large fuel supply to natural gas, and has since reported a substantial reduction in carbon emissions and improved energy efficiency. The purpose-built mill commenced production in 2010. It manufactures more than 250,000 tonnes of animal feed annually, supplying customers in Northern Ireland and the border region in the Republic of Ireland.

Ronan McCanny, Fane Valley Feeds operations director, said: “Fane Valley Feeds is part of the Fane Valley Co-operative Society which has a number of businesses now connected to natural gas.

“Converting the fuel supply to our boilers from oil to natural gas has lowered our carbon emissions by 34 per cent and improved our energy efficiency,” he added. •