The share price of AIM-listed potash exploration firm African Potash surged on Monday after its Chief Executive Ed Marlow showed optimism about the industry in an interview on CNBC's 'Squawkbox' programme.Potash is the common name for many potassium-bearing materials and compounds and is used mainly as a soil fertiliser, being the third major plant crop nutrient after nitrogen and phosphorus.Asked whether potash will be a "big money-winner" for companies, Marlow said: "It's impossible to produce at the levels that people want to produce agriculturally without it, and the demand has to increase as population explodes."Marlow said that the potash contained within his company's exploration areas is "some of the best", in terms of grade, distance beneath the ground and closeness to the sea.He foresees potash prices at around $300-330 per tonne which is "perfect" for miners producing it at below $100 a tonne.African Potash is currently advancing the Lake Dinga Potash Project in the Republic of Congo in which it holds an indirect 70% interest.The stock was up 14.29% and at 3p on Monday.BC