The Emperor, a keen naturalist and conservationist, visited Wells Farm in Little Milton, Oxon, on the final day of his trip.

But there was no sign of any war veterans protesting as they had done on several occasions earlier in the four-day state visit.

The Emperor was given a guided tour of the specialist farm, which combines natural techniques with conservationist policies.

Wearing a pair of binoculars around his neck, he had a glimpse of a pair of rare red kites and was shown a re-planted apple orchard, as well as a rare black poplar tree.

The Emperor had asked to visit a working farm after reading an article in a British newspaper about conservationist farming.

A secret revealed

The tour had been kept a closely-guarded secret. But crowds of Japanese media followed the Emperor.

Afterwards, local wildlife trust director Martin Spray said the Emperor had shown a wide knowledge of the countryside.

He said: "He was particularly interested in the red kites which have recently been reintroduced into England having been absent for 100 years.

"The Emperor was also very impressed with the black poplar tree and with the wild flowers.

"He found it all extremely interesting and it was a good opportunity to show him what we are doing in British farming."