The most common and most likely answer to this crossword clue is the 12 letter word CONSERVATION
I've seen this crossword clue in The Guardian
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More clues leading to the result CONSERVATION
- Safekeeping of satin cover on ground
- Conversation is about management of natural resources
- Careful management of refurbished cast-iron oven
- Keeping going in dialogue, getting two characters to switch around
- Environmental issue has two characters in conversation switching positions
- Exchanging very small talk, maintaining historic buildings
Buddy explains!

The straight part
We know that "management of natural resources /management of natural resources" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case management of natural resources /management of natural resources = conservation.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CONSERVATION mean?
CONSERVATION noun- The act of preserving, guarding, or protecting; the keeping (of a thing) in a safe or entire state; preservation.
- Wise use of natural resources.
- The discipline concerned with protection of biodiversity, the environment, and natural resources
- Genes and associated characteristics of biological organisms that are unchanged by evolution, for example similar or identical nucleic acid sequences or proteins in different species descended from a common ancestor
- (culture) The protection and care of cultural heritage, including artwork and architecture, as well as historical and archaeological artifacts
- Lack of change in a measurable property of an isolated physical system (conservation of energy, mass, momentum, electric charge, subatomic particles, and fundamental symmetries)