29 October 2014

Sirius Minerals Plc

Chilli Pepper and Celery Crop Study Results

§  Independent crop studies concluded on chilli pepper and celery - which have a combined global market value of $3.1bn

§ Studies demonstrate all four nutrients in POLY4 are of value to the crops and available in a quality, low-chloride form

§ Results also included improved yields over synthetic alternatives when matched across the macro-nutrients

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.

The studies were conducted on high-value crops, celery and chilli pepper, in the United Kingdom at the University of Warwick, and in the US at Texas A&M respectively.

The total world market value for each of these crops is significant - with global chilli pepper production representing a market value of US$2.7 billion in 2012 and celery representing a market value of US$458 million in 2012.

The studies, undertaken in a controlled environment, demonstrate the value of POLY4's macro nutrients.  The results further the agronomic understanding of POLY4 and continue to build evidence about its beneficial use:

§ 20% increase in celery potassium uptake levels over MOP, leading to higher crop yield and higher fertilizer use efficiency;

§ POLY4 outperformed MOP as a straight fertilizer on celery dry weight by 22%;

§ On a K2O basis, POLY4 outperformed MOP on chilli pepper yield by 10% and further outperformed SOP, the premium potassium fertilizer, by an additional 3%; and

§ In a separate balanced trial on chilli pepper yield POLY4 outperformed MOP by 11% and SOP by 2% when these alternative potassium sources were fully balanced with POLY4 for sulphur, magnesium and calcium applications.

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

" These encouraging results demonstrate POLY4's nutrient availability and efficiency of use from this preferred source of essentially chloride-free potassium."

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 .