Barley Crop Study Results

13 November 2014

Sirius Minerals Plc

Barley Crop Study Results

§ Independent crop study in the UK on barley shows POLY4 outperforming MOP and SOP on yield and other agronomic measures

§ Results demonstrate how POLY4 use can be a significant opportunity to reduce farming costs at the same time as maximising yield

The Directors of Sirius Minerals Plc (AIM: SXX, OTCQX: SRUXY) ("Sirius" or the "Company") are pleased to provide an update on the latest results from its ongoing global crop study programme.

This field study was conducted on barley, in the United Kingdom, at the University of Warwick Crop Centre. Barley is a significant crop grown on approximately 50 million hectares globally and 1.1 million hectares in the UK. The studies demonstrate the particular value of POLY4's potassium and sulphur content as well as the added benefits of low chloride levels and the other nutrients contained within POLY4.

Results of note from this barley trial include:

§ POLY4 increased yields over MOP and SOP by 4.10t/ha and 0.6t/ha respectively;

§ POLY4 increased winter season survival rates compared to both MOP and SOP; and

§ POLY4 maximised macro and micro nutrient uptake compared to both MOP and SOP

Chris Fraser, Managing Director and CEO of Sirius, commented:

"These encouraging results demonstrate POLY4's capacity to maximise yield and minimise fertilizer input costs at the same time. Given the importance of barley to UK agriculture these results will not only be of interest here in the UK but also globally."

An agronomy update presentation and webcast has been uploaded to the Company website www.siriusminerals.com.

For further information, please contact:

About Sirius Minerals Plc

Sirius Minerals is a potash development company with properties in the United Kingdom (North Yorkshire) and the United States (North Dakota). Its primary focus is the development of the York Potash Project which has the world's largest and highest grade deposit of polyhalite, a multi-nutrient form of potash containing potassium, sulphur, magnesium and calcium. Incorporated in 2003, Sirius Minerals' shares are traded on the London Stock Exchange's AIM market. Its shares are also traded in the United States on the OTCQX through a sponsored ADR facility. Further information on the Company can be found at www.siriusminerals.com.