There were dozens of projects focusing on farming at last week’s BT Young Scientist exhibition, and several students taking part in the competition specifically researched the links between agriculture and climate change.

Young scientists tackle farm emissions.

Soil compaction the enemy

Orla Good and Laoise O’Mahony from Kinsale Community School in Co Cork investigated the effects of soil compaction on autumn carbon sequestration in grassland.

The capacity of farmland to capture carbon is not yet fully known and improving this in a measurable way could help Irish farmers offset their emissions from livestock and fertiliser.

The two students conducted pressure tests to measure soil compaction in three fields, showing that some areas were more compacted than others.

They also took soil samples at the 20 measuring points and heated it in a furnace at 400°C for three hours, which burns off the organic material – 58% of which is carbon.

By substraction, this allowed them to measure the carbon content of the soil on two occasions, in October and December.

“There was a significant increase in non-compacted soil, but none in compacted soil,” said Orla.

One limitation of the study is the amount of fallen leaves that may have affected the results, she added.

Tilling is also a factor in soil compaction and carbon release from the soil, and the students sampled two fields ploughed two years apart, one four years ago and one two years ago.

“The four-year-old field had more organic matter than the two-year-old field,” said Orla.

“Non-compacted soil sequesters more carbon,” concluded Laoise.

This should encourage the use of machines putting less pressure on the soil, such as variable pressure tyres on slurry spreaders, she added.

Orla and Laoise were highly commended by the judges for their project.

Orla Good and Laoise O'Mahony at the BT Young Scientist Exhibition in Dublin. \ Thomas Hubert

With grass growth and nutrient availability other factors in increasing efficiency and reducing greenhouse gas emissions, research by Niamh Hegarty and Eimear Collins from Choláiste Choilm in Ballincollig, Co Cork, confirms the importance of reducing soil compaction to address climate change.

They measured 80% faster grass growth in non-compacted soil compared with heavily compacted soil, and a 28% improvement in grass yield between the two samples.

“The roots can’t force through the compacted soil because there is so much bulk density,” said Eimear.

There were also 50% more worms, 17% more water and significantly more phosphorus and potassium in non-compacted soil, said Niamh.

Niamh Hegarty and Eimear Collins from Choláiste Choilm in Ballincollig, Co Cork at the BT Young Scientist Exhibition in Dublin. \ Thomas Hubert

Electricity from manure

Garet Molloy from Belvedere College in Dublin created a microbial fuel cell to generate electricity from chicken manure from his neighbour’s farm.

“This is nature’s biological battery,” said Garet. Bacteria feeding on the manure generate electrons and protons, which he captured with conductive material forming the anode – the positive side of the battery.

The cathode, or negative side, rests in a water solution. By connecting the two, Garet generated an electrical current, but it was very weak.

To amplify this, he designed a booster electronic circuit capable of amplifying a 50mV input to a 4.5V output.

“This could power lights or phones,” Garet said, adding it could benefit farmers without access to the electricity grid such as many in Africa.

In addition, one of the by-products of the chemical reaction is clean water.

His experiment involved only a few grams of manure and could be scaled up: “Imagine the potential,” he said.

Processing manure would also help reduce the net greenhouse gas emissions of livestock farming, Garet said.

“We’re trying to help save the planet by supplying electricity for people who need it most while reducing farmers’ footprint.”

Garet won the junior individual first prize in the biological and ecological studies category for his project.

Garet Molloy from Belvedere College, Dublin at the BT Young Scientist Exhibition in Dublin. \ Thomas Hubert

Dairy farmers are ready

All this knowledge and technology is well and good, but are farmers ready to use it? Jack Keena and Tadhg Henegan from Colaiste Mhuire in Mullingar, Co Westmeath, conducted a wide survey across the dairy industry in November and December to find out.

“I got the idea because I live on a dairy farm. I saw the drought and the late spring,” said Jack.

The two students interviewed 103 dairy farmers in their community, in Teagasc discussion groups and at the national dairy conference.

Only 3.8% said they had suffered no impact from harsher weather conditions, with all others reporting increasing feeding, labour or property damage costs.

“95% said climate change was either important or very important,” Tadhg said, and 87% would attend training on the issue.

Only around half believed there was enough research in this area.

The two students also asked farmers and dairy processors what they were doing to tackle climate change.

The farmers surveyed reported good soil sampling, liming and fertiliser management, and 40% said they had switched to trailing shoe slurry spreading.

Co-ops cited the SDAS and Origin Green schemes as their main mode of action.

Jack and Tadhg also asked farmers the controversial question of who should pay fines if Ireland is found in breach of its greenhouse gas emissions targets.

Some 60% said they wanted to be given a chance to reduce emissions from their farm to avoid a fine, while numbers around 20% each favoured either a fine appropriate to each farm’s emissions, or a system spreading fines evenly among all farmers.

Jack Keena and Tadhg Heneghan from Colaiste Mhuire, Mullingar, Co Westmeath. \ Barry Cronin

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