All new farming techniques in the UK should be assessed for their environmental impact before they are introduced, leading scientists say.
Non-GM crops could also be assessed for environmental impact
The call comes from the Advisory Committee on Releases to the Environment (Acre), a body that advises the British government on GM crops.
New farming practices do not currently require major risk assessment unless they involve genetic modification.
But an Acre report says this approach is too narrow and should now change.
The report was requested by Environment Secretary Margaret Beckett.
It was prompted by the results of the Farm Scale Evaluations (FSEs) - extensive, four-year-long experiments that investigated the impact on biodiversity of four genetically modified crops.
The biotech plants were compared with conventional varieties and significant differences in the presence of weeds and insects were noted - but these had little to do with genetic modification per se, researchers found.
Rather, they resulted from the different field management practices (times of weedkiller spraying, etc) employed to grow each crop.
"This then led to the question of how we might look at regulation in the future, given that our current regulatory system is orientated around one or two issues, like GM, but ignores elements of agriculture that could have as great or even greater impact on the environment," explained Professor Chris Pollock, chair of Acre.
The report states that in addition to using economic sustainability as a marker for introducing novel farming practices, an evidence-based approach should be applied to examine any environmental risks and benefits.
While this would not mean having to carry out experiments of the same scale as the FSEs, said the scientists, it might mean that the methods used for the FSEs could be "stripped back" to assess some new crops.
The FSEs looked at changes in biodiversity in the trial fields
They stressed that the regulatory burden would not be placed upon farmers, but would be the responsibility of those seeking to introduce the crop or new practice.
Professor Jules Pretty, one of the authors of the report, who is based at the University of Essex, said it was important to assess the benefits of new technologies as well as the harm.
"We suggest the need for a new approach, a new paradigm, for setting out the way we do regulation in agriculture."
Common Agricultural Policy (CAP) reform, which removes the link between crop production and subsidies, will drive great changes in farming over the next decade, and the scientists said that it was important to consider the environmental impacts that this could bring.
"We've had changes in agriculture ever since agriculture began," said Professor Pollock.
"But we are now getting to the stage where the impacts of a range of agricultural systems are really quite marked, and society has asked scientists, regulators and farmers to do something about this. The whole point of this document is that it is a touchstone for this debate."
All farmings practices will change the natural landscape to some degree
It highlights examples of current agricultural practices that have retrospectively shown to have a huge impact on the environment.
"The shift from hay cutting to silage had enormous implications for all sorts of aspects of the countryside and biological diversity," explained Professor Pretty.
"The old hay meadow would have lots of different flowers in it, but silage is made before the weed season."
The report will now be circulated for discussion before a final copy is submitted to the Department for Environment, Food and Rural Affairs (Defra).