I first wrote an agritourism story for the NYTimes ten years ago (“Historic Hybrid in Iowa” published Nov. 26, 2000) – and even then it wasn’t all that new. But now comes word, again from the NYTimes, that agritourism is alive and well (or “gaining ground from coast to coast”) My story years ago was about the Garst Farm in Coon Rapids, Iowa. This was a real workaday farm that takes overnight guests and offers activities like riding, fishing and hiking. It also has a distinguished history. In 1958, Soviet Premier Nikita Khrushchev visited as part of efforts to improve his country’s agriculture.
Now there are several websites where you can find farms to visit and even work on. See Worldwide Opportunities in Organic Farms (wwoofusa.org) and Ruralbounty.com, a national agritourism registry.
Interestingly, I looked up Garst Farm on Ruralbounty.com and found it’s now part of something called Whiterock Conservancy (see http://www.whiterockconservancy.org/accomodations.aspx)
TakeBetsywithyou 
Hi Betsy, I enjoyed reading your ’00 NYTimes article on Garst Farm Resorts. Having worked at the, now, Whiterock Conservancy for nearly two years, I’ve watched the slow evolution of the B&B into not only a place of recreation and relaxation, but also a conservation model for the rural landowner. Whiterock Conservancy, a non-profit organization, is in charge of stewarding one of the Midwest’s largest private land gifts (a total of 5,400 acres from the Garst family). We are a working landscape practicing various aspects of sustainable agriculture, restoring oak savanna and planting native prairies. Our efforts positively impact the water quality of the Middle Raccoon River as well as create habitat for a variety of wildlife. Visitors can enjoy hiking our 30+ miles of trails through woodlands and prairies, or canoeing an 8-mile stretch of the Middle Raccoon. For more information on our work, upcoming events, to book a stay or make a donation, you can visit http://www.whiterockconservancy.org.
thanks for the update