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.
This land has high natural fertility, so crops grow well without using much chemical fertilizer.
The soil's fertility has declined due to continuous cropping.
Compound of 地 (chi, 'earth, land') and 力 (ryoku, 'power, strength'). The reading ちりょく is a standard on'yomi combination.