The hilly Palouse region had been farmed that way for decades.But the tillage was taking a toll on the Palouse, and its famously fertile soil was eroding at an alarming rate.

• 丘陵起伏的帕劳斯地区曾持续这种农耕法数十年，却因此付出代价，著名的肥沃土壤在那段时间侵蚀的速度著实令人忧心。