We took a group of AF Members, with colleagues from our Fertiliser & Member Services teams and representatives from AF supplier Origin Soil Nutrition, on a trip to the Yorkshire coast to go deep underground to understand the story of this UK natural fertiliser.
To help our Members with their fertiliser choices we want to deepen their understanding of crop nutrition.
Into the depths – the underground tour
A 7-minute decent into complete darkness, and with the temperature reaching 40-43°C, a 35-minute drive along the mine tunnels took our group 5 miles offshore and 1,400m below ground to the active polyhalite mining face.
The scale and structural complexity of the mining operation was incredible. At the mining face, workers gave a tour of the machinery. They work 12-hour shifts in 4-day rotations. The harsh environment, with its heat and dust, earned our group’s full respect. AF Member Rodger Hobson and AF’s Liz Osborne even tried out the cutting machine – an exciting, hands-on experience!
After four hours underground, our group returned to the surface alongside miners finishing their shifts. Despite the tough conditions, there was clear camaraderie and pride among the workforce.
“This mine tour was an exciting opportunity. Although I’ve often walked the nearby cliffs, I've never ventured below ground. I’m interested to better understand the mine’s logistics, especially why fertilisers are still transported by sea despite the proximity of many farms.”
The science of crop nutrition
ICL Product Development Manager Mark Allen gave technical insights to the agronomic benefits of ICL’s Polysulphate and Potash Plus:
Low carbon footprint - polyhalite is simply crushed and screened at the Boulby site, to produce Polysulphate. No chemical processing means lower carbon footprint.
Balanced combination of nutrients - 48% sulphur, 17% calcium, 14% potassium & 6% magnesium.
Gradual nutrient release - aligns more closely with crop uptake, improving efficiency and reducing loss through leaching.
Sulphur delivery - at 48% SO3, Polysulphate is predominantly a sulphur fertiliser. This is now the deficient nutrient in UK soils.
Flexible nutrition – use as a straight sulphur source to compliment variable rate P & K and any form of nitrogen, both solid and liquid. Or buy as part of an NPK prescription blend.
Organically approved – Polysulphate fits in with organic sources of nutrition, such as manures or digestates, which are short of sulphur too. As a non-nitrogen source of sulphur, it compliments any nutritional programme.
A polyhalite core sample from ICL Boulby
ICL Technical Sales Manager Richard Ward shared field trial results, showing up to 40% yield improvements thanks to prolonged nutrient availability and improved nitrogen use efficiency from Polysulphate.
The session gave Members an excellent opportunity to ask about integrating Polysulphate into their own fertiliser nutrition plans. Particularly, if it would still be effective and dissolve in dry conditions. Richard explained tests show it dissolves with minimal moisture, making it suitable even during drier spells.
“The session was highly informative, especially in light of recent soil sample data showing up to 70% of UK soils tested are deficient in sulphur—highlighting a real opportunity for improvement.”
View from the producer’s perspective
For ICL, AF’s visit was an opportunity for Members (either already using or considering using their products), colleagues and supplier Origin Soil Nutrition to see first-hand the sweat and effort that goes into producing Polysulphate and PotashpluS. It gave a unique chance to discuss the benefits of using ICL’s products and how they can be applied in the field.
“Visits like this are invaluable for building customer relationships and both educating, and being educated by, our customers. We’ve seen annual growth of sales in the UK market since being first sold in 2012, as more and more farmers are coming to realise the benefits and flexibility of the products.”
Have we got you thinking about your crop nutrition plans? For products, prices, and insights talk to your AF Fertiliser team today.
