你先把你所谓的“粮食”定义清楚了

Corn for grain production in 2017 was estimated at 14.6 billion bushels, down 4 percent from the 2016 estimate. The average yield in the United States was estimated at a record high 176.6 bushels per acre, 2.0 bushels above the 2016 average yield of 174.6 bushels per acre. Area harvested for grain was estimated at 82.7 million acres, down 5 percent from the 2016 estimate.

Sorghum grain production in 2017 is estimated at 364 million bushels, down 24 percent from the 2016 total. Planted area for 2016 is estimated at 5.63 million acres, down 16 percent from the previous year. Area harvested for grain, at 5.05 million acres, is down 18 percent from 2016. Grain yield is estimated at 72.1 bushels per acre, down 5.8 bushels from 2016. 

Rice Production in 2017 totaled 178 million cwt, down 20 percent from the 2016 total. Planted area for 2017 was estimated at 2.46 million acres, down 22 percent from 2016. Area harvested, at 2.37 million acres, was down 23 percent from the previous crop year. The average yield for all United States rice was estimated at 7,507 pounds per acre, up 270 pounds from the 2016 average yield of 7,237 pounds per acre. 

Soybean production in 2017 totaled a record 4.39 billion bushels, up 2 percent from 2016. The average yield per acre was estimated at 49.1 bushels, 2.9 bushels below the record yield in 2016. Harvested area was up 8 percent from 2016 to a record high 89.5 million acres.