IPA: //ʌnˈfɜːr.tɪl//
KK: /ʌnˈfɜr.tɪl/
Not able to produce plants or crops; lacking the ability to support growth.
The soil in that area is unfertile, making it difficult to grow any vegetables.
Unfertile → It is formed from "un-" (meaning not) and "fertile" (from Latin "fertilis", meaning fruitful or productive). The word "unfertile" means not fruitful or lacking the ability to produce crops or offspring.
Think of 'not' ('un-') being added to 'fruitful' ('fertilis') — that's why unfertile means not able to produce.