By Rod Nickel and Polina Devitt WINNIPEG, Manitoba, Feb 1 (Reuters) - Nutrien Ltd NTR.TO, the world's biggest potash miner, could boost production by up to 29% in coming years, depending on any sanctions facing rival producers in Russia and Belarus, the Canadian company's interim CEO told Reuters. Soaring fertilizer prices have cut in to farmers' incomes and contributed to global food inflation. "They are so used to just controlling things in the industry and have started to believe their own marketing about having excess capacity," Ferguson said.