I could not be more honoured and delighted to receive this award, and particularly from someone whom I have known and admired for such a long time. When we first met, in 1982, Hardy Vogtmann had just become the world's first Professor of Organic Agriculture. He has since been a State Minister of Agriculture and now he is President of the German Federal Agency for Nature Protection. In all three roles he has been a thoughtful and inspiring figure, and I am glad to have the opportunity to say so in public.

I could not be more honoured and delighted to receive this award, and particularly from someone whom I have known and admired for such a long time. When we first met, in 1982, Hardy Vogtmann had just become the world's first Professor of Organic Agriculture. He has since been a State Minister of Agriculture and now he is President of the German Federal Agency for Nature Protection. In all three roles he has been a thoughtful and inspiring figure, and I am glad to have the opportunity to say so in public.

I also wanted to thank Claus-Peter Hutter, President of Euronatur, and his colleagues for deciding to make this award. I see that it is almost two years since they first reached their decision, so I only hope I have not done anything since then to cause them to want to change their minds!

When I made my first speech about the environment, in 1968, I said that I could claim no expertise about the countryside, but that I had a very deep love and attachment to the country. Well, some things do not change! I can still claim no particular expertise, and I still love to be in the countryside whenever I can.

In the 33 years since that first rather tentative speech, I have also thought quite a lot about the relationship between mankind and the environment that sustains us. It may be an unfashionable assertion, but I am convinced that the natural world has bounds of balance, order and harmony that set limits to our ambitions.

When we exceed those limits, or attempt to over-ride the complex, natural system of checks and balances, we will always end up, sooner or later, paying a heavy price. In some cases, as with fish stocks in the North Sea (and in many other parts of the world), we have made painful discoveries about where those limits are.

In other situations, as with climate change, we do not yet know the precise extent of the problems we will face. But we know more than enough to justify precautionary action - which is why I was so pleased to see that all the EU nations have now signed the Kyoto protocol. This sort of joint commitment to action seems to me to be the only appropriate response to a genuinely global threat. I can only hope that others will follow the European lead.

In both the cases I have just mentioned, recognising the nature and the extent of the problem is, of course, just the first essential step of many. We also have to do something about rectifying the problem, and it is here that I believe we are being absurdly unambitious. In fact I sometimes think that, as a species, we have a strange sense of priorities!

We are prepared to allow ever more intensive forms of animal husbandry on land, using methods that are often both unsustainable and unnatural. Yet we cannot find the international political will even to think about returning our fish stocks to the sustainable and natural levels of less than 40 years ago - when there were three times as many of the "table fish" species in the North Atlantic as there are now.

All the discussion seems to be about stopping the decline, and of course that is essential. But what about actually improving the situation? Is not this the case in which getting back to where we were - with abundant stocks of a wild, natural resource - would be the best possible investment in the future?

I recognise, of course, that improving an existing situation, using a combination of traditional knowledge and modern methods, will always be regarded as a great deal less exciting than doing entirely new things, and that these are likely to be more profitable, at least in the short term. Exciting, innovative, profitable approaches are also likely to attract the greatest share of research funds. Nowhere is this more apparent than in the field of agriculture.

When Hardy Vogtmann described our first meeting in 1982 just now, he mentioned my suggestion that there was a need for some proper research in the field of organic agriculture. Well, I have made the same point a good many times since then! So you can imagine my pleasure at discovering that an impeccable academic study, just published by the Department of Land Economy at Cambridge University, reaches the same conclusion.

The authors say that "there is a strong case for more R&D funds to be made available for organic agriculture". They explain that this would help organic farming to catch up, in terms of productivity, with conventional farming, which they say has "benefited from extensive research" over the last 60 years.

They also point out that "the existing imbalance in the technological development of the two farming systems is likely to put organic agriculture at a distinct disadvantage" - a disadvantage which (they say) "has escaped the eyes of many commentators". And they conclude that "a long-term research strategy for organic agriculture would aim at rectifying this imbalance and help to improve the efficiency of organic production, thereby making it more attractive and profitable". And I could not agree more.

I certainly hope that policy makers and funders of research projects will take some notice of this recommendation. But at the moment the emphasis seems to be on supporting research into genetically-modified crops which, regardless of any possible environmental threat, certainly pose an acute threat to organic farmers, and to all those consumers who wish to exercise a right of choice about what they eat.

The extent of the problems of contamination is becoming clearer and clearer. So I find it hard to understand how the companies which will profit from having developed these crops, and which are taking out patents to ensure that they do, should be able to avoid taking liability for any damage that occurs.

The public, meanwhile, are making their own preferences known, and organic food consumption is growing at more than 15% a year. And at this point I have to declare a personal interest.

As Hardy has just mentioned, 10 years ago I started a company called Duchy Originals. I wanted to demonstrate that it was possible to produce food of the highest quality, working in harmony with the environment, using the best ingredients and adding value through expert production. I also wanted to engender increasing funds for my Charitable Foundation, which receives all the profits.

The first product, a biscuit, was soon followed by other items, including preserves, soft drinks, bread and sausages. We now have a thriving organic brand, with over 50 product lines and a turnover of £14 million per year.

I have also started to achieve my financial ambition, because my Charitable Foundation has already received £1.5 million in profits, with which I am able to support initiatives to do with the environment, sustainability and regeneration.

For example, last year I was able to give half a million pounds to the farming charities who have been doing so much to help the families affected by the outbreak of Foot and Mouth Disease.

Duchy Originals is growing at more than 50% a year, and I am happy to say that Germany is our largest export market. One of the most rewarding aspects of the business is seeing a whole range of specialist suppliers, many of them small family businesses, growing with us and sharing in the success. I have also started investigating possibilities for helping small producers in developing countries.

When I visited Guyana three years ago I learnt that cocoa used to be a major cash crop for the country, but that the industry had been redundant for 30 years. I suggested to the President that he might think about re-developing it - using some of the old cocoa plantations - to supply beans for Duchy Originals chocolates.

To my delight, he agreed and the project has worked out very well, so far. A small co-operative of 26 farmers and their families was set up and their beans have just received organic certification. I hope to be using them in Duchy Originals chocolate later this year - in time for Christmas.

I certainly did not set out to create a "case study in sustainable agriculture" with my venture in Guyana, but there is a virtuous circle which I intend to try to repeat elsewhere, and which I believe other food producers and retailers could follow.

Our strong consumer brand is supporting the development of small, but locally significant, community projects. These projects are based on the most sustainable form of agriculture and help to maintain thriving communities. And the developed world consumer has the satisfaction, not only of eating exceedingly good chocolate, but also of knowing that their purchase has helped maintain a dignified and more sustainable lifestyle in the developing world.

I want to end by briefly discussing a subject which I know is a fundamental aim of Euronatur, and which also lies close to my own heart, and that is the preservation of traditional, cultural landscapes.

One of the weaknesses of modern scientific method is that it is not very good at "the big picture". It can look at any one element of the picture in stupefying detail, at any level from the cosmic to the molecular, but it is not designed to provide the sort of broad, multi-disciplinary over-view that is required when looking at a subject like landscape and the countryside.

I do hope organisations like Euronatur, with its commitment to public education, might help to explain the extent to which our traditional, cultural landscapes have been shaped, with their characteristic flora and fauna, by countless generations of our forefathers.

We need to communicate the fact that the people, the wildlife, the land on which they live, and, indeed, the type of products that are produced, are inextricably linked, and always will be.

Even something as apparently simple as the decision by some wine-makers to use plastic stoppers instead of the traditional cork can have far-reaching impacts. Quite why anyone should want to encounter a nasty, plastic plug in the neck of a wine bottle is beyond me! Yet this growing practice is causing major changes in the dehesas of Spain and Portugal.

The production of cork from the oak trees of the dehesas is a sustainable industry. The trees live for centuries and the bark can be stripped every nine years. And the dehesas provide a rich and varied wildlife habitat, particularly for birds and butterflies. But all this is under threat, with a real possibility that if demand continues to decline the cork oaks will be replaced by fast-growing eucalyptus, or other non-native species.

When traditional farming systems die out, the wildlife and the landscape will soon (by which I mean after a generation or two, at most) be unrecognisable. Where, for instance, villages are allowed to die through lack of services, or monocultural arable systems are developed on a prairie scale, or traditional upland grazing systems cease to operate, there will inevitably be major changes, not just for the human inhabitants, but for wildlife and the landscape too.

These, in turn, can have an impact on other economically-important activities, such as tourism. Which reminds me, Ladies and Gentlemen, that when it comes to tourism linked to traditional, cultural landscapes, have you noticed how those who most loudly pour scorn on so-called "inefficient peasant-farming systems" and the small, family, mixed farms wherever in the world they might be, are the ones who most frequently take advantage of the very real benefits that they bring whenever they get away from their offices - the food, the wine, the villages, the atmosphere provided by an ancient "sustainable" landscape?

It is, of course, these more traditional methods of farming that bring so many other benefits and, at the end of the day, actually make so much of rural life worthwhile; that invest it with meaning, with joy, with spiritual value, with eccentricity, and above all, with culture.

When we are weighing up the pros and cons of different systems of farming, please let us remember to include these wider benefits which also have an economic value. All my life so far I have been motivated by a desire to re-create lost habitat, whether of the landscape or of the mind and soul; to reinstate the "culture" in Agriculture, as opposed to the "industry" in Agri-industry.

Agri-industry will always be inherently unsustainable as it overrides those bounds of balance, order and harmony that I mentioned at the outset. Sustainability surely means the acceptance of certain limits - as with, for instance, the application of highly sophisticated technology in the fishing industry which is now clearly inappropriate in relation to the fragile state of fish stocks.

How else can we possibly protect the interests of future generations - of people as well as fish? It is a tragedy that such desperate battles have to be fought to establish sensible limits, but fought they have to be.

The decision to stop large-scale peat extraction from lowland raised bogs in Yorkshire, for instance, is likely to lead to re-creation of a scarce habitat, much richer wildlife, increased opportunities for tourism and recreations and a new local industry based on peat alternative. It is an excellent example of sustainability in action and all those who worked so hard to reach this conclusion deserve to be congratulated.

In conclusion, I just wanted to emphasise that, as far as I am concerned, the most important factor in all the situations I have mentioned, ranging from the cork oaks of Iberia to fish stocks in the North Sea, via organic cocoa in Guyana, is to accept that all our actions have consequences, and that mankind has a duty of stewardship for the natural world.

The degree of skill, commitment and foresight - in other words "wisdom" - we apply to that duty will shape our own destiny, and that of our children.