The phrase "a key subject for" is correct and usable in written English.
It can be used when discussing an important topic or theme relevant to a particular context or field of study.
Example: "Climate change is a key subject for discussion at the upcoming environmental conference."
Alternatives: "an important topic for" or "a significant issue for".
A major problem is the low number of girls at school who study physics, a key subject for careers in engineering and construction.
Down-hole operating condition diagnosis based on dynamometer card is a key subject for sucker rod pumping in oil extraction engineering.
The investigation on natural circulation (NC) characteristics of the China Advanced Research Reactor CARR) is very valuable for practical engineering application and also a key subject for the CARR.
The release of Sowing the Seeds coincides with the launch of Reporting on Agriculture and Women: Africa, a three-year IWMF initiative to enhance reporting on agriculture and women in Africa and make agriculture a key subject for African media.
The bill morphology of avian granivores is a key subject for palaeoecological research.
Surveillance is a key subject for the control and prevention of infectious diseases and provides information about main epidemiological and microbiological aspects to put in place correct strategies.
Due to the long lasting consequences, school-to-work related inequality of educational opportunity (IEO) has been a key subject of empirical educational research for years.
If the prediction sounds familiar it's because de Grey – this time described as a gerontologist – was subject to a similar profile in Friday's New York Times, thanks to his being a key subject of Jonathan Weiner's book Long For This World: The Strange Science of Immortality.
The issue is likely to be a key subject of debate when the Conservatives meet for their annual conference in Birmingham on Sunday.
"The state of F1 has been a key subject within the sport for several months, and this weekend F1 commercial boss Bernie Ecclestone has given an interview on the subject to BBC F1 chief analyst Eddie Jordan.
The accident analysis, limited to the area of design basis accident, constituted the key subject for the study; therefore, the notorious Chernobyl unit 4 event was outside the scope of the investigation.
