noun:

• crab shell (often ground or crushed and used as fertilizer); crab shell meal

noun:

• fish cake (made from sardines, used as a fertilizer); sardine meal

noun:

• oil cake (fertilizer made of oily vegetable dregs)
• deep-fried meat (esp. beef offal) resembling a pork rind ［油かす］ - Food term ➜ かす饂飩

noun:

• tank for holding excreta (often used for fertilizer) (fertiliser); night soil vat or reservoir

noun:

• tank for holding excreta (often used for fertilizer) (fertiliser); night soil vat or reservoir; cesspool

noun:

• dried and pressed boiled herring (used as fertilizer)

godan ~す verb / transitive:

• to give (time, money, goods); to donate
• to do; to perform; to conduct
• to apply (processing, makeup, etc.); to add (e.g. ornamentation, annotation)
• to sow; to seed; to scatter (e.g. fertilizer); to sprinkle
• to spread far and wide - archaism