How things have changed.

Twenty-five years ago, a man with 80ha (200 acres) of good wheat land or 60 dairy cows could apparently make a good living for himself and his family.

In fact, such a business could probably support two generations, plus a full-time employee or two.

Turn the clock forward to 2006 and you find that farming's ability to support even a single family, never mind sons and daughters, is sorely diminished.

These days 200ha (500 acres) of owned land might produce £15,000, but you'll have to run a car and energy-hungry farmhouse out of that.

So 320ha (800 acres) would be better, although it all depends how efficient a producer you are and how modest your lifestyle is.

Faced with declining returns, farmers have acted logically and sought income from other sources.

Cottages have been rented out, phone masts erected, bed and breakfast established.

Diversification, rather than expansion, has become the orthodox route to survival.

But what if you haven't got the often-substantial funds needed to start a farm diversification?

The answer, to adapt Norman Tebbit's famous phrase, is to get on your bike and look for off-farm work.

Some smaller farms have done that for decades, working part-time on the farm and part-time for a local contractor or at the farm supply shop.

The difference now is that the need to find extra income is affecting most - if not all - farm businesses across the UK.

But becoming a part-time farmer is both more acceptable and more feasible these days, says Strutt and Parker's Will Gemmill, himself a farmer's son.

"When I was growing up, there was a feeling that someone had to take over the farm full-time and it was seen as failure if no one did," he says.

"Now, thanks to bigger tractors and one-pass crop establishment systems, farms that used to be run on a full-time basis can now be run part-time.

"It's more difficult on livestock farms, but many of the principles still apply.

"I think many farmers' children can see that there isn't a full-time job there any more and know that they will have to do something else as well.

That's not necessarily a bad thing - many people like the variety of having two jobs and meeting different people."

The hardest part is often deciding what non-farm job you want to do.

Time for a little business self-analysis, says Mr Gemmill.

"One thing farmers haven't traditionally been good at is putting a financial value on their own time," he says.

"They would spend hundreds of hours in the farm workshop making a set of rolls when it probably would have made better sense buying a set off the shelf and spending the time on something that produced a direct profit.

"You need to ask yourself if it's really sensible to continue farming the whole farm in-hand.

It sounds disloyal to say it, but it may be more sensible to bring in contractors and use your time for something that has better profit-earning potential."

David Cousins