Potato Review

18 POTATO REVIEW MARCH/APRIL 2020 A new source of fertiliser being mined from beneath the North Sea is offering potato growers improved performance in the field and in crop quality for processing, according to speakers at a recent technical conference on the role of sulphur in crop production, organised by ICL Fertilizers. Polyhalite is a mineral extracted by ICL at its Boulby mine in the North Yorkshire moors and is commercially available in a 2-4mm granular spreadable form. It has a low carbon footprint of just 0.033kg CO2e. The product is marketed as Polysulphate and provides four essential macro nutrients – sulphur, potassium, magnesium and calcium. Owing to its complex crystal structure, the nutrients in the product are released more slowly compared to existing fertilisers and this gives added benefits, particularly for those on light soils, the manufacturer says. Sulphur is an essential nutrient needed for a range of plant functions and for making essential amino acids and proteins within the crop. It is also needed to ensure crops make the most efficient use of nitrogen. The formation of vital plant proteins in crops such A sea-sourced solution Mineral extracted in Yorkshire examined by agronomists. as potatoes also appears to improve cooking qualities and gives a benefit to the food processors and consumers. Independent soil analysis by Lancrop Laboratories has shown an increasing deficiency of sulphur in UK soils. While 60% of soils tested in 1995 were sulphur deficient; by 2017 this had increased to 97%. This is attributed to a massive reduction of atmospheric deposition from industrial operations owing to the Clean Air Act. As a result, all the conference speakers agreed that there is a nationwide need for sulphur fertilisation. ICL Agronomist Scott Garnett spoke about trials on potatoes which the company has been undertaking together with independent researchers and ICL dealers. This work has shown improved crop performance from including polysulphate in the fertiliser programme. “In 2019 we conducted one series of trials on four potato varieties using Polysulphate and PotashpluS (a granular compound of Polysulphate and potash). In the trial the addition of PotashpluS increased yield from 42t/ha to 57t/ha against the normal ➜ PotashpluS vs MOP FERTILISATION FOCUS Scott Garnett