Latest Crop Study Webcast

30 April 2014

Sirius Minerals Plc

Latest Crop Study Webcast

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 on-going global crop study programme.

Recent studies conducted at the University of Florida, Durham University and Shandong Agricultural University have been completed on a variety of crops including sugarcane, soya bean, corn, oilseed rape ("OSR") and potatoes. These studies were undertaken in both the field and pot study environments and were focused to analyse the multifaceted characteristics of polyhalite that continue to demonstrate improved yield response and flexibility in crop husbandry.

This latest set of results have confirmed material yield increases for the globally significant crops of sugarcane, soya bean, corn, wheat, potatoes, and OSR. Improvements have been seen in both straight and blend applications with increased nutrient use efficiency demonstrated through greater yield gains when applied as part of fertilizer blends (NPK's).

In addition to the crop study data released in the webcast, the Company has also released information on the presence of key micro-nutrients found in its POLY4 products which come from the York Potash Project such as boron, manganese, zinc and molybdenum. In a number of previous trials, as shown in the 27 January 2014 webcast, natural polyhalite has outperformed synthetic polyhalite. For example, at recommended K2O levels for OSR, natural polyhalite increased seed fresh weight per plant by 10% over synthetic polyhalite. The Company believes that this meaningful increase is likely to be contributed to by the essential micro-nutrients naturally found in polyhalite in the York Potash Project.

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

"Our on-going global crop study programme continues to demonstrate the beneficial impact of polyhalite on major valuable crops throughout the world. With sales commitments for millions of tonnes already in place across four continents it is clear that there is an extremely large, and growing, market for this important multi-nutrient mineral."

"Sirius will continue to lead the charge in marketing polyhalite around the world, the value of which is increasingly understood by customers, competitors and governments alike."

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

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About Sirius Minerals Plc

Sirius Minerals is a globally diversified potash development company. Its primary focus is to bring on stream major potash mining facilities through the acquisition and development of projects overlying recognized potash deposits. Today it holds properties in the United Kingdom (North Yorkshire) and the United States (North Dakota). 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.