As Neville Chamberlain’s famous declaration of war rang out across the nation in September 1939, we were importing 55 per cent of our food — 90 per cent of our cereals, 70 per cent of our cheese and sugar, 80 per cent of our fruit and 50 per cent of our meat.

With supply lines cut or critically endangered, the Government exhorted Britons to ‘Dig for Victory’. Farmer and householder alike took up the rallying call. Farming output rose significantly within months and we were able to avoid defeat by starvation.

As peace returned, food security was still a raw wound, rationing continued, nations devastated by war had to be fed and crippling debt stifled imports. The Government resolved to maximise food production at any cost.

The Agriculture Acts of 1947 and 1957 were primarily aimed at offering farmers long-term stability in prices and subsidies, to encourage investment in agriculture.

Joe Henson wanted to enter agricultural college in 1949, but was unable to do so, as he explained: “There was a long waiting list for places, lots of ex-Services people wanted a career after demob, so I had to wait until 1952, when I was 20.”

In the meantime, he took a job on a mixed farm at Tetbury. Then, after management positions on two Gloucestershire farms, Joe and his business partner John Neave secured the tenancy at Bemborough Farm near Stow on the Wold. Their initial 400 acres has expanded to 1,600 today — 650 hectares — as they gradually took over land from retiring tenants. The Agriculture Acts have given long-term security to the tenancy.

“The change to larger fields, ploughing up ancient grasslands and rooting out walls and hedges was purely government-driven,” Joe explained. “John and I had a big overdraft and families to feed, so we weren’t going to refuse £14 an acre to grub up a pasture, much as we didn’t like doing it.”

Joe is in doubt that the war dramatically influenced the swing to mechanisation. The need to wring every last ounce of grain from the soil and the limited manpower available from the Land Army pushed the growth in the use of tractors and machinery. Once the war was over, the heavy horse was doomed.

“Lots of the people who were trained in using horses had died in the war,” Joe said. “Those who came back to the land did not want hours of grooming and cleaning tack. They preferred to sit on a tractor.”

Crop yields have risen dramatically over the years, a combination of mechanisation, agrichemicals and better plant strains.

“Yields have improved ten per cent year-on year,” said Joe’s business partner, Duncan Andrews. “The plant biologists have worked wonders and still do on increasing resistance to disease, pests and drought, and matching plants to particular soil conditions.”

But intensive farming, brought about by pure economics, is not without its problems. The old three-year crop rotation of wheat, barley and then grass has gone, especially since the decline of livestock farming. There are neither the animals to eat the grass, nor the manure to fertilise it. Lack of rotation increases the risks from diseases and weeds.

Duncan said: “We had 99 per cent control over black grass, which can lose you one tonne a hectare of cereal if you get over 100 grass heads per square metre. But the grass has now grown resistant to the herbicides and Essex has a real problem. In some parts, control is down to 45 per cent.”

By the 1960s, Britain was producing an abundance of cheap food. This was to lead to oversupply and food mountains. When we joined the EU in 1973, the Common Agricultural Policy wrought major changes in farming.

Initially, EU subsidies were on production such as tonnage per acre, or the number of lambs or calves reared. As oversupply hit, that became a unit subsidy, such as so much per hectare of land, or per ewe or per cow. The result was that farmers increased livestock far beyond normal levels and a quota system, based on annual stock counts, became the norm.

Joe’s son, Adam, recalls trading stock quotas in the 1980s. “If you had more quota than stock, you could sell your excess quota at £10 per head. The buyer then claimed his subsidy at £18 per head. I bought and sold quota, it was like stocks and shares.”

Set aside became the buzzword, but for conservation, was largely futile. By law, farmers had to cut the set aside at exactly the time when the birds were nesting or they did not get paid.

Most farming now is arable, but heavily dependent on volatile market forces such as the drought in Russia and the flooding in Pakistan. The days of a minimum or intervention price for cereals, or a guaranteed price from the Milk Marketing Board are long gone. Dairy farmers negotiate contracts direct with supermarkets, struggle to make a profit and can be ruined if the contract is cancelled.

Bio-ethanol alternative fuel production is now taking 1.8-2m tonnes of the UK’s 14m tonnes soft wheat output. This not only lessens the quantity available for food, but drives up prices into the bargain.

For the farmers, the business cycle is one of following the latest Government brainwave, most of which last a couple of years. Planning has become a game of chance, second-guessing what the next initiative will be.

But, farming is showing a well-deserved resurgence. Consumer pressure has improved farming practices beyond all measure. Buyers want quality local produce that can be traced back to source and food security is again an issue. While farming subsidies are decreasing, environmental subsidies are available to balance the books.

Natural England, the Government’s eco and wildlife advisor, now employs some very savvy people who understand farming and work with the farmers on environmental schemes.

Diversification brings additional income. Bemborough Farm has joint ventures with two neighbours, sharing manpower and equipment to maximise efficiency and reduce overheads. Their rare breeds farm park, started by Joe in 1971, is an integral part of the operation.

Media work, such as BBC’s popular Countryfile programme, brings not only revenue, but encourages visitors to the park.

Adam regularly lectures at agricultural colleges and finds them all full of students.

Land-based diplomas in schools, apprenticeships and fresh-start schemes are all encouraging people back to the land.

“Farming will always be hard work,” said Adam. “But now it demands more young people with high-tech skills. The modern tractor has a built-in computer, steers itself by GPS and works out the ideal pattern to till a field. It is exciting stuff — farming really is a growing business.”