Farmable soil, if you go to purchase it, costs four dollars a pound.

可耕地的土壤，如果你去购买它，价格是四美元一磅。

But every cubic meter of soil requires 40 liters of water to be farmable.

但每立方米的土壤需要 40 升的水才能耕种。

Farmable soil, if you go to purchase  it, costs four dollars a pound.

可耕种的土壤，如果你去购买，每磅要 4 美元。