What is an irony mentioned in the passage?

Imports such as corn from Romania and soyabeans from India are booming, according to an analysis of US trade data released on Wednesday by the Organic Trade Association.

Rising consumer demand in what’s been a niche market is creating shortages, pushing companies that supply farms needing organic feed to seek out foreign sources.

Most of the corn and soyabean shipments become feed for chickens and cows so they can

be certified organic under US Department of Agriculture guidelines.

Organic poultry and dairy operators shun feed made with seeds from domestic suppliers in favour of foreign products even as the US remains the world’s top grower of corn and soyabeans.