"Something had to be grown in rotation with corn." Scott Jackson, professor of plant genetics at Purdue University.

VOA: standard.2010.02.01

He says the soil is worn out, partially due to poor crop rotation.

VOA: standard.2010.04.01

The vote was seen as a major setback for Mr.Topolanek as it came just days before a planned visit by United States President Barack Obama and midway through the rotation of the Czech Republic's European Union presidency.

VOA: standard.2009.03.25