In mid-March, Beijing banned exports of nitrogen-potassium fertiliser blends and certain phosphate varieties, sources told Reuters.

The ban, which has not been formally unveiled, was reported earlier this week ​by Bloomberg News.

Added to existing bans and export quotas for urea, only a handful of fertilisers – notably ammonium sulphate – can be exported, five sources ​said. That would mean between half and three quarters of China‘s exports last year are restricted, potentially up to 40 ⁠million metric tons, according to a Reuters estimate.