noun
fertility (of soil); natural productivity (of land)
Refers to the inherent ability of soil or land to produce crops, often contrasted with added fertilizers or human effort.
この土地は地力が高いので、化学肥料をあまり使わなくてもよく育つ。
This land has high natural fertility, so crops grow well without using much chemical fertilizer.
連作で地力が落ちてしまった。
The soil's fertility has declined due to continuous cropping.