The Family Farm Action Alliance has asked the U.S. Department of Justice to investigate whether recent spikes in fertilizer prices are attributable to market manipulation by fertilizer companies. Prices hit record highs again this week with Anhydrous Ammonia at an average retail national price of $1,372 per ton, up another 18% from last month. Alliance President Joe Maxwell alleges that is being driven up artificially by the industry which is the basis for the investigation.

Global fertilizer prices have hit record highs this year, in part due to the soaring prices for natural gas used to produce them and severe weather events that disrupted U.S. production. But Maxwell alleges fertilizer firms are using those as excuses and are hiking prices in response to high commodity prices.

Maxwell adds that fertilizer companies have refused to produce to capacity, which is adding to the shortage.

A spokesman from Mosaic stated that fertilizer companies don’t set prices and the current spike is due to curtailed exports from various nations, including China, and strong global demand, among many factors.