WASHINGTON — The preliminary national average price received by farmers for all wheat in December was $7.05 per bu, up 92c from $6.13 in November and up $2.18 from $4.87 in December 2009, the U.S. Department of Agriculture said in its latest Agriculture Prices report.

The average price paid for winter wheat in December was $6.85 a bu, up 85c from $6 in November and up $2.17 from $4.68 in December 2009. The average price paid for durum was $6.83 per bu, up 79c from $6.04 in November and up $1.92 from $4.91 in December 2009. Spring wheat other than durum averaged $7.38 per bu, up $1.02 from $6.36 in November and up $2.20 from $5.18 in December 2009.

The average price paid for rough rice in December was $12.90 a cwt, up $1.10 from $11.80 in November but down $1.50 from $14.40 a year earlier.

The December index of prices received for food grains was 229 compared with the 1990-92 base of 100, up 16% from 198 the previous month and up 33% from 172 in December 2009.

The December index for feed grains was 207, up 7% from 194 in November and up 34% from 155 in December 2009. The average price paid to farmers for corn was $4.94 a bu in December, up 39c from $4.55 in November and up $1.34 from $3.60 in December 2009. Farmers received an average of $9.17 a cwt for grain sorghum in December, up 73c from $8.44 in November and up $3.46 from $5.71 in December 2009. The average price paid for oats in December was $2.74 a bu, down 28c from $3.02 in November but up 52c from $2.22 in December 2009.

The index of December prices received for oilseeds was 204, up 7% from 191 in November and up 19% from 172 in December 2009. Farmers received an average of $11.70 a bu for soybeans in December, up 60c from $11.10 in November and up $1.90 from $9.80 in December 2009.

The December index for dairy products was 129, down 6% from 137 in November but up 2% from 126 in December 2009. The average price paid to farmers for manufacturing grade milk in December was $14.70 a cwt, down 90c from $15.60 in November and down $1.60 from $16.30 in December 2009.

The poultry and egg index was 154, down 4% from 161 in November but up 10% from 140 in December 2009.

The average price paid to farmers for all eggs in December was $1.08 a dozen, down 5c from $1.13 in November but up 3c from $1.05 in December 2009.