It was a bold step for the Royal Agricultural Society of England (RASE) to ask the head of a supermarket chain to be its president. True, Lord Sieff and Alastair Grant had held this post before me - but not at a time when there was so much tension between farmers and super­markets. My presidency year has greatly strengthened my personal conviction that the future of farming is an urgent issue for this country and that supermarkets can't duck their responsibility.

Farming isn't just about farmers. It matters as much to urban dwellers as it does to rural communities. Three quarters of the UK land mass is occupied by farming of some kind and our 'green and pleasant land' depends on a thriving agri­culture sector. Landscape, bio-diver­sity and conservation are all public benefits provided as free bi-products of food production. They cannot sensibly depend on the public purse.

So, when we read about farm incomes falling by more than 60% and UK self-sufficiency in food declining by more than 15% over the past decade, we shouldn't brush this off as "farmers always complaining". There's a trend here with national implications. The consequen­ces will be felt by our grandchildren, but the ability to act before the 'tipping point' rests with us today.

Ahead of this year's Royal Show I commissioned a report for RASE examining agriculture in the UK. In particular, I asked for information on the attitude of customers. Previous research had shown a disparity between consumers' concerns and their shopping patterns: more than 80% recognise the importance of farming, but less than 20% are ready to pay more to buy British.

Our latest report brought out three reasons for this reluctance: consumers were ready to pay more for quality or taste rather than for ethical factors; they saw super­market advertising focusing only on price and suspected them of pocketing any price differential intended for British food producers; and they doubted that their individual purchasing decisions could make a difference.

The sustainability of food production in the UK can't be based on artificial market structures forcing shoppers to pay more for their food. It depends, therefore, on a response to each of these three points.

First, farmers should be encouraged to differentiate their products from world-priced commodities. High environmental and animal husbandry standards and confidence about taste and quality add up to a product that shoppers will prefer to buy. Second, supermarkets need to build transparent and supportive relationships with British producers, backed by clear labelling and information. And third, consumers need to appreciate that ultimately their individual shopping decisions will determine the viability of British agriculture.

As part of my RASE presi­dency, I've championed initiatives designed to bridge the gap between farmers and consumers. Workshops for farmers have been directed at improving their competitiveness and skill in marketing their products; 'Meet Your Local Farmer' visits to Waitrose shops promote greater understanding between farmers and consumers; and the Farmer for All Seasons scheme aims to increase consumer awareness of seasonality and support for local produce.

A lead must come from government. David Milliband, secretary of state for Defra, said at the Royal Show: "Farming is at the heart of our society, economy and cultural heritage." We all have a part to play in ensuring that heart remains healthy.