The two sides at loggerheads over land used by breeding stone curlews will have to wait for the outcome of a High Court challenge.
The owner says the decision could affect the value of his land
Mr Justice Lightman, the judge hearing an appeal for the special status given to 33,000 acres of Breckland to be overturned, said he recognised the importance of the case and was reserving judgement until a later date.
The move came after two days of intense legal argument about the designation of the land as a Site of Special Scientific Interest to protect the stone curlews.
Norfolk landowner the Honourable Patrick Fisher said English Nature misunderstood its role when it designated his land on the Norfolk-Suffolk border as a rigorously protected site.
He is spearheading the High Court challenge on behalf of local farmers who want English Nature's decision in Breckland overturned.
He said the decision could have a dire impact both on the management of his land and on its value and asked the High Court to overturn it.
He told the court he is all for helping to conserve the rare birds but the loss of so much land would be detrimental to his livelihood.
The birds are recognised as needing special conservation measures and English Nature insists there was nothing irrational about its decision.