It's a tough time to be a farmer.

Just ask Rachael Sharp, a slot third-generation farmer in the US state of South Carolina, who grows a varied mix of soybeans, corn, wheat, cotton, peanuts and oats.She saw fertiliser prices for her crops soar 320% last year - the sharpest rise that she, or her father, can remember.

Ms Sharp says some of her fellow farmers aren't planting anything due to the excessive costs.Around the world, prices of fertilisers have been breaking records over the past year, amidst extreme weather, transport disruptions, and now the Russian invasion of Ukraine.

Russia, which is contending with Western sanctions, produces large quantities of key chemicals used in the production of fertilisers. It also supplies much of the natural gas used to produce ammonia - a major component of nitrogen fertilisers.