ScienceDaily: An important agricultural region in China is drying out, and increased farming may be more to blame than rising temperatures and less rain, according to a study spanning 30 years of data. A research team led by Purdue University and China Agricultural University analyzed soil moisture during the growing season in Northern China and found that it has decreased by 6 percent since 1983. The optimal soil-moisture level for farmland is typically 40 percent to 85 percent of the water holding capacity,...