Agricultural research in the UK could face a serious skills shortage at a time when the world is struggling to ensure that it can feed the human population.
The warning comes from the Royal Society, which is midway through a major study exploring how science can help to enhance global food production.
It coincides with renewed interest in this area by funders - last week, the research councils announced a new programme focusing on "food security".
John Beddington, the Chief Scientific Adviser, recently said that the world faced a "perfect storm" of dwindling food, water and energy supplies that would strike in around 2030 unless action was taken.
But scientists on the Royal Society's food-crop production working group have said that the science required to tackle the problems could be hampered by a lack of researchers in relevant areas. They highlighted the falling number of students pursuing agricultural sciences and university departments teaching the subjects over many years.
Ian Crute, a member of the group and director of the Rothamsted agricultural research centre, said: "Unless we address the decline in researchers working in this area now, we may not have enough scientists to train the next generation."
There was some cause for hope in figures from the Universities and Colleges Admissions Service, which show that about 2,400 students applied to study agriculture this year, a rise of 7.2 per cent compared with last year.
The Royal Society's study is due to be published in November.