I know, you told me,

The speaker is acknowledging that they have been informed or explained something by someone else.

your nightsoil and all your city’s, goes still warm every morning

The waste generated by the city, referred to as “nightsoil,” is collected regularly, and the reference to it being “still warm every morning” suggests its fresh and recent collection.

in a government lorry, drippy (you said)

This waste is transported in a government truck, and the term “drippy” implies that it is not fully solid but somewhat moist or wet.

but punctual, by special arrangement to the municipal gardens to make the grass grow tall for the cows in the village, the rhino in the zoo: and the oranges plump and glow, till they are a preternatural orange.

Despite its wet nature, the waste is collected reliably and taken to municipal gardens. There, it serves as a fertilizer, contributing to the growth of tall grass for village cows and zoo rhinos. The oranges grown in these gardens become unusually bright and large, described as “preternatural orange.”

Good animal, yet perfect citizen, you, you are biodegradable. you do return to nature: you will your body to the nearest hospital, changing death into small change and spare parts;

The person is praised for being both a good animal (in harmony with nature) and a perfect citizen. The focus here is on the person’s natural quality of being biodegradable, indicating that their body will naturally decompose and return to nature. The mention of willing the body to the nearest hospital suggests a willingness for organ donation after death, turning the process into spare parts.

dismantling, not decomposing like the rest of us. Eyes in an eye-bank to blink some day for a stranger’s brain, wait like mummy wheat in the singular company of single eyes, pickled, absolute.

The poem contrasts the person’s fate with the rest of humanity. Instead of decomposing like everyone else, this person’s body will be dismantled. The eyes may be preserved in an eye bank, waiting to be used for someone else. The comparison to “mummy wheat” suggests a state of preservation, and the use of “pickled” reinforces the idea of a preserved or absolute state.

Hearts, with your kind of temper, may even take. make connection with alien veins, and continue your struggle to be nationalized. beat, and learn to miss a beat, in a foreign body-

The focus shifts to the heart, suggesting that even the heart, with its unique qualities, might be used for transplantation. The idea is that it could connect with different veins and continue to beat in a foreign body, implying the possibility of a heart transplant. The phrase “struggle to be nationalized” adds a layer of complexity, suggesting a metaphorical struggle for integration into a new body.