Prices for all eight of the major types of fertilizers critical to farmers have increased over the past month following the U.S.-Israeli war with Iran, according to trade magazine the Progressive Farmer.

Fertilizers are among the top input costs for farmers, with price spikes arriving during planting season in much of the world. Citing government and industry forecasts, the New York Times reported that produce prices could rise 6 percent, bread and cereal could increase 10 percent, and ground beef could rise by 7 or 8 percent.

Many nitrogen-based fertilizers are derived from natural gas, with about 30 percent of the world’s fertilizer passing through the Strait of Hormuz, now restricted by Iran. Prices for four major fertilizer types have seen double-digit increases in the past four weeks, the outlet reported.