Crop prices closed higher Tuesday ahead of a government report that is expected to show tighter corn supplies next year.

On Wednesday, the U.S. Department of Agriculture is set to release its monthly survey of global grain and bean supplies. It's the first government report since farmers harvested their crop last month.

Traders believe that the U.S. corn harvest will be smaller this year because of an unusually hot summer. Corn hit a record price of $7.99 a bushel in June on fears of a shortage in 2012. Prices have fallen since then after farmers planted the second biggest corn crop since World War II.

Corn for December delivery rose 7.25 cents Tuesday, or 1 percent, to settle at $6.605 per bushel. December soybeans rose 3.25 cents to $12.05 a bushel. December wheat gained 18.25 cents, or nearly 3 percent, to finish at $6.57 per bushel.

Last month, the USDA predicted that farmers will have about 866 million bushels of corn on hand at the end of 2012. That's enough to satisfy demand for about 23 days. Most traders think a 30 day supply of corn is a healthy surplus level.

Farmers harvested about 85 percent of their corn in October. Wednesday's report will be the first that uses actual tallies of this year's harvest, rather than relying on estimates, said Jason Ward, an analyst with Northstar Commodity in Minneapolis. Most analysts expect the report will show that an unusually hot summer reduced corn yields from Kansas to Illinois.

In other commodities trading, metals were mostly higher. Gold for December delivery rose $8.10 to settle at $1,799.20 per ounce. December silver rose 32.5 cents, or nearly 1 percent, to close at $35.153 an ounce.

Copper for December delivery fell 0.25 cents to close at $3.5533 per pound. December palladium rose $15.35, or 2 percent, to close at $677.25 an ounce. January platinum gained $15.10 to finish at $1,673.10 an ounce.

Benchmark crude oil gained $1.28, or 1.3 percent, to end at $96.80 per barrel on the New York Mercantile Exchange.

Heating oil fell 0.37 cents to finish at $3.1161 per gallon, gasoline futures lost 2.18 cents to close at $2.7064 per gallon and natural gas gained 4 cents to close at $3.843 per 1,000 cubic feet.