With the price of fertiliser recently confirmed to have risen by over 90% between November 2021 and November 2022, farmers may be seeking alternatives to an artificially made granule.

This is what Roscommon Community College student, Sean Allen, aimed to do with his project for this year’s BT Young Scientist and Technology Exhibition (BTYSTE).

Sean’s project, titled ‘The long-term effects of a more sustainable method of keeping nutrients in the soil as an alternative to an artificially made granule’, won first place in the biological and ecological senior individual category of the competition.

Sean told Agriland that he knew the rising prices of fertiliser were hard for farmers to keep up with, and that he was eager to find a solution.

“I decided to research this project because it is currently a hot topic in the farming world as the EU is regulating synthetic fertilisers heavily in the next number of years as it is contributing heavily to climate change,” he said.

He decided to test digestate and waste milk as an alternative to 10-10-20 fertiliser, with the hope that it would prove to be a better, more sustainable, and more cost-effective way of keeping nutrients in the soil.

Findings

The patches of grass Sean used for his project

Sean explained that he found that a mix of digestate and waste milk was the best for grass growth and that it grew more, on average, compared to the other treatments he tested.

“The milk and digestate are adequate alternatives because the grass grew more when the two were mixed than the 10-10-20 on its own,” he said.

“The digestate grew better than the 10-10-20 on its own too, on average.

“Then the dry matter tests showed that they are a good alternative even more so, because the digestate and milk on their own lost less dry matter than the artificial fertiliser, which shows the quality of the grass is better.

“This could be because the digestate and waste milk is organic and natural compared to the 10-10-20.

“My research fits the current research and it shows that I have potentially found a sustainable, organic alternative to artificial fertiliser that could possibly rival commercial fertiliser on the market.

“It’s offering a greener solution to farmers with the same results in grass yields.”

The future

Sean said his digestate and waste-milk mix outperformed 10-10-20 fertiliser on every test he did, and was what he himself would recommend to farmers because of the results of grass quality and growth.

Sean’s teacher, Conall Moore, could not be more complimentary of Sean’s project. Moore is even implementing Sean’s project findings on a larger scale – on his own farm.

“We’re hoping now to apply digestate as a top dressing on spring barley this year,” Moore said.

“On my own farm at home, we grow tillage crops, and from Sean’s project I got the idea of applying digestate now in spring and winter barley as well, so we’re actually going to try the project large-scale on my farm at home.

“It seems to be something that could be viable, especially on winter crops by the looks of it.

“Especially down the line for tillage farmers it be would be something to consider because there is such a supply of phosphorus and nitrogen from it and it is something that could be applied on crops via an umbilical or dribble bar system. It is something that could be done large-scale.”

A sustainable and cost-effective alternative

Both Sean and his teacher cite the digestate and waste-milk mix as a sustainable and cheap way to keep nutrients in the soil.

“This is a waste product; this is a product that has to go somewhere anyway. And it’s being thrown out and it has so much potential,” Moore said.

Sean’s comparison of prices of 10-10-20 fertiliser and digestate

“Whereas we’re importing nearly all of our chemical fertiliser and this could be used too. The science shows, and Sean’s project has shown, that it can replace fertiliser.

“At the moment, Sean’s project shows it can replace (artificial fertiliser) to grow grass, so it can replace and grow other crops. It’s completely sustainable.

“As felt by every farmer in the country the price [of fertiliser] has skyrocketed for a number of reasons,” Sean explained.

“Farmers and government alike know that this price is unsustainable for any farmer trying to keep stock fed and crops managed.

“An alternative like anaerobic digestate and waste milk is needed to be found to try and manage the growth of crops and the health of the soil instead of paying an astronomical price for an artificial granule.”