Polysulphate®: a natural and eco-friendly fertilizer

A multi-nutrient, multi-tasking crop nutrition solution
April 20, 2021
Polysulphate®: a natural and eco-friendly fertilizer

Polysulphate is a new multi-nutrient fertilizer mined in the UK by ICL. It is a natural mineral (polyhalite). Uniquely, Polysulphate contains four key plant nutrients. They occur in the following proportions: sulphur (48% SO3), potassium (14% K2O), magnesium (6% MgO) and calcium (17% CaO) - all in sulphate (SO4) form.
Being a natural crystal, as soon as it is applied to the soil Polysulphate has a gentle way of breaking up and releasing the four nutrients it contains gradually. This useful prolonged release characteristic of Polysulphate means that as nutrients are released, they provide a continuing fresh source to the growing crop, matching the nutrient needs of crops.
The special solubility nature of Polysulphate provides a prolonged release of sulphur; this reduces the risk of leaching in sandy soils and under high precipitation. Its prolonged release of nutrients makes it less prone to leaching losses thus preserving the environment.

Steadfast and reliable nutrient supply for all crops
Applying Polysulphate supplies growing crops with all the sulphur, magnesium and calcium needed, and replaces a significant proportion of the potassium that would otherwise be removed at harvest and this avoids a potassium deficit for the following crop.
It is extremely convenient and cost-effective for farmers and growers to provide four essential nutrients to their crops in just one application. An additional advantage is that having the four key nutrients in the right combination and quantity helps to achieve the enhanced quality that is so crucial in fresh produce in order to be able to market it easily and achieve the best possible financial returns.
Polysulphate is an ideal natural fertilizer for all type of soils and crops. It is especially suitable for sulphur demanding crops like brassicas, cereals, pulses, field vegetables, clover-rich grassland leys and silage crops. The sulphur in Polysulphate promotes the utilization of nitrogen by the plant, thus increasing the nitrogen use efficiency (NUE). Balancing sulphur with nitrogen nutrition is crucial for enhanced protein formation.
Due to its low content of chloride (Cl), Polysulphate also presents a new fertilizer solution to crops which prefer low levels of Cl in the soil (such as tea, tobacco, grapes and other fruits), and where higher dry-matter content is required in potatoes. Also, with its neutral pH, Polysulphate does not adversely affect the pH of the soil.

Polysulphate – pure and simple and approved for use in organic farming
Polysulphate easily meets the criteria for use in organic farming systems because it is a natural fertilizer product. Unlike blended or compound fertilizer, Polysulphate is available in its natural mineral state.
From mining deep below ground in Cleveland, UK, the polyhalite mineral is brought up to the surface and simply crushed, screened and bagged as Polysulphate ready for transport through the supply chain to farms around the world. There is no chemical separation, or any complex industrial process involved: it is naturally good and perfect for use with all crops.
Polysulphate is approved for use in organic agriculture and has organic certificates in UK, France, Germany, Austria, Italy, the Netherlands, Hungary, Poland, Brazil and Israel. In addition, Polysulphate standard and granular grades are OMRI-listed for organic use in USA and Canada.
Polysulphate has been included on the international list of inputs allowed for organic farming according to EC 834/2007, NOP (National Organic Program, USA) and JAS (Japanese Agriculture Standard) regulations.
Polysulphate is not only an excellent option for organic farmers but also for conventional farmers who are looking for a low-cost, environmentally positive source of four key nutrients for their crops. Along with prolonged multi-nutrient availability and ease of application to a wide range of crops, low carbon footprint is now another benefit of Polysulphate that is attractive to organic and conventional producers alike.

Polysulphate trial on organic onions in the Netherlands on a sandy loam soil (2016): the application of 360 kg of Polysulphate/ha increased total bulb yield by 580 kg/ha. Half of the higher yield was in larger bulb onions (> 6 cm diameter), increasing by 13%.

Choose Polysulphate to lower carbon footprint of farming
The results of a new study show that Polysulphate has the lowest carbon footprint when compared with alternatives. Compared with a wide range of equivalent fertilizers, Polysulphate has the lowest carbon footprint, at 0.034 kg CO2e per kg of product. It is so much lower that it is less than 3% the carbon footprint of ammonium nitrate.
The added benefit of low carbon footprint is making Polysulphate the fertilizer of choice for those farmers carrying out carbon counting on their enterprise and wanting to lower their greenhouse gas emissions and carbon footprint.

Polysulphate® carbon footprint compared with other commonly used fertilizers, as calculated by Filkin & Co EHS Limited in November 2019

Naturally good for crops and the environment
Taking all these positive unique characteristics of Polysulphate together, it is no surprise that farmers all over the world are choosing to use Polysulphate on their crops. Whether they are growing for grains, fruits, shoots, roots or tubers, Polysulphate is a fertilizer that is both crop-friendly and environmentally friendly and fast becoming a key crop nutrition tool in sustainable agricultural production all around the world.
For more information, visit www.polysulphate.com


This article was originally published in the special issue Precision Agriculture 2021

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