Not only had the market been flooded, but also the soft 'yellow ground' had been mostly  exhausted, giving way to harder 'blue ground' which had to be broken with machinery or dynamite.

不仅市场被淹没，而且柔软的“黄地” 已经大部分被耗尽，取而代之的是坚硬的“蓝地” ，必须用机械或炸药来破坏。