Translation guide
In Japanese, the most common word for fertilizer is 肥料 (hiryō). There are also more specific terms for chemical vs. organic fertilizers, as well as related words for compost and manure.
The general term for any substance added to soil to help plants grow.
The standard, neutral word for fertilizer in all contexts.
この肥料は野菜によく効きます。
This fertilizer works well for vegetables.
肥料をまく時期は春です。
The time to apply fertilizer is spring.
Specifically synthetic or inorganic fertilizer.
Literally 'chemical fertilizer'. Commonly used to distinguish from organic types.
化学肥料を使いすぎると土が悪くなります。
If you overuse chemical fertilizers, the soil deteriorates.
Fertilizer derived from natural sources.
Literally 'organic fertilizer'. Used in gardening and farming contexts.
有機肥料は安全で環境に優しいです。
Organic fertilizer is safe and environmentally friendly.
Decayed organic material used as fertilizer.
Specifically compost or manure that has been decomposed. Often used in agricultural contexts.
堆肥を作るには時間がかかります。
It takes time to make compost.
Loanword from English, often used for home composting systems.
Animal dung used as fertilizer.
Specifically animal manure, often from livestock. More technical than 堆肥.
厩肥は窒素を多く含んでいます。
Manure contains a lot of nitrogen.
肥料 (hiryō) is the broadest term for any fertilizer. 堆肥 (taihi) refers specifically to compost or decomposed organic matter, while 厩肥 (kyūhi) is animal manure. In everyday conversation, 肥料 is usually sufficient.
I put kitchen scraps in the compost bin.