Sioux Falls, SD (AP) - Federal agriculture officials say the number of farms in South Dakota dropped by about 400 last year. The U.S. Department of Agriculture's National Agriculture Statistics Service says the number of farms and ranches closed the year at 31,300. That's down 400 from 2014. The state lost 100 farms and ranches with less than $100,000 in agricultural sales while operations with more than $100,000 were down 300 farms from 2014.The total land in farms and ranches in South Dakota totaled 43 million acres, which is unchanged from 2014. The average size of operations, at 1,383 acres, was up 17 acres from a year earlier.