The 37.5% Arable Rent Reduction Act Article 9

(Objects of rents)The lessee shall still pay the agreed main crops as rent even if he (lessee) cultivates other crops during the growing seasons of the agreed main crops. But he (lessee) may pay rent in cash, or by the said other crops, converted from the agreed main crops according to market value of the locality, if the lessor agrees.
中文原文 耕地三七五減租條例第9條
承租人於約定主要作物生長季節改種其他作物者,仍應以約定之主要作物繳租。
但經出租人同意,得依當地當時市價折合現金或所種之其他作物繳付之。

English translation for reference only; the Chinese text prevails. Not legal advice.