The total number of farms and ranches in South Dakota decreased during 2014 by about 300 agricultural operations from the previous year, according to researchers with the U.S. Department of Agriculture.

The National Agricultural Statistics Service released information on Thursday, indicating that the number of South Dakota farms and ranches had dropped to 31,700.

The USDA found that the amount of land in ag production had remained constant during the past two years at 43.3 million acres. However, the average size of farms had increased by 13 acres to an average of 1,366 acres per farm in South Dakota.

Several of the overall trends for South Dakota's ag operations followed national trends with the number of U.S. farms declining from 2.1 million in 2013 to 2.08 million in 2014. USDA data showed that farm operation numbers have stayed in a steady decline since 2007 with national ag operations falling from 2.2 million during that year.

Nationally, the amount of farm land that has stayed in production has also declined from 921 million acres in 2007 to 914 million acres in 2013 to 913 million acres in 2014. Across the United States, the average farm size has increased from 418 acres in 2007 to 435 acres in 2013 and to 438 acres in 2014.

The USDA's definition of a farm includes any operation that has $1,000 or more of ag products produced or sold, or normally would have sold, during a year. Ranches, institutional farms, experimental and research farms, and tribal reservations are included as farms.

The 2012 USDA data for Lake County showed that the county had 502 farms in operation with about 262,000 acres in production. The same census data showed Miner County had 486 farms and about 357,000 acres in production. Moody County had 513 farms and 254,000 acres in production.

The 2012 information also showed that the average farm size in Lake County was 521 acres with Miner County at 735 acres and Moody County at 496 acres.

USDA researchers also classify South Dakota farms according to their values of sales in seven categories, ranging from less than $2,000 annually to $100,000 or more annually.

This week's USDA information said that the number of farms in South Dakota which had less than $100,000 in annual agricultural sales fell by 400 farms from 2013 to 2014. However, the ag operations that had more than $100,000 in annual sales grew by 100 farms during the past year.

In Lake County, the 2012 census data showed that 210 out of the 502 farms had $100,000 or more in annual sales. The same data indicated that 140 farms in Lake County produced less than $2,500 in annual sales.

The USDA reported this week that in 2014, about 51 percent of the farms in the U.S. had annual sales between $1,000 and $10,000. The USDA uses different economic sales categories for its national farm data. Those smaller farms produced agricultural goods from about 10 percent of the nation's farmland on ag operations that averaged 86 acres in size.

The $10,000 to $100,000 annual sales class provided the next largest category at about 30 percent of farms growing products on about 21 percent of U.S. farmland with the average farm size at 312 acres.

Ag operations with annual sales of $1 million or more made up about 4 percent of the nation's farms with about 24 percent of U.S. farmland in their operations and an average size of 2,655 acres.