U.S. almond farmers are getting crunched from all sides as they head into what is likely to be a record harvest season.

Prices for California almonds have fallen by more than 10% over the past two months, reflecting expectations for a bumper crop and steep tariffs imposed this year by China, which until recently was the second-largest importer of U.S. almonds after the European Union.

In response to China’s tariffs, which now add a 50% tax to almond prices, some Chinese businesses say they are trying to buy more nuts grown domestically and from other producers such as those in Australia and Africa.

And in yet another setback for U.S. farmers, China has quietly closed a trading loophole that for years allowed large volumes of American almonds to be transported into the country via Vietnam without incurring import taxes. Beijing is also cracking down on commodities that have been illegally smuggled into the country or brought in via transshipments, where they are routed to other countries and then shipped to China.

The moves reflect China’s efforts to make its tariffs on U.S. agricultural products as effective as possible. Almonds are likely to be among the hardest hit, because the U.S. is the world’s largest producer and exporter of almonds, with 80% of the global supply coming from California.