David Lambert, who is also professor of geography education at London's Institute of Education, said this drive, coupled with government targets, meant that learning was in danger of becoming "banal". He said that, to stop subject teaching from being marginalised, the profession needed to rediscover its sense of moral purpose.
He praised the new secondary curriculum for geography that the Qualifications and Curriculum Authority (QCA) is introducing, saying it had the potential to improve pupils' understanding radically.
But it was in danger of being swallowed up by schools rushing to replace subject-specific work with cross-curricular, skills-based teaching, which places the emphasis on "learning to learn".
Writing in the latest edition of the education journal Forum, Professor Lambert said: "Teaching outside an area of subject expertise risks banality: banal, because it may lack the theoretical and conceptual frameworks that can support critical engagement leading to deeper understanding."
He said that allowing secondary teachers to "delve deeper and linger longer" with their subjects would encourage more to stay in the profession. But he said that some heads were making curriculum decisions not for educational reasons, but to maximise value-added scores.
This was apparent in the move, which increasing numbers of secondary schools have made, to shrink key stage 3 to two years so pupils can spend more time preparing for GCSE.
Professor Lambert said Ofsted's inspections were now heavily influenced by exam results and that test targets had "perverted" the curriculum. "We have a crisis in schools, and it is to do with the curriculum," he said. "It has been caused by the way we treat teachers - or, more precisely, the way teachers' work has been configured, in a highly technicist manner with low risk, compliance and very high stakes."
An extract of Prof Lambert's article, published today, can be viewed at www.wwwords.co.ukforum.