On the future of agriculture
In less than thirty years, we will reach a historical moment in the history of humankind when the era of land expansion, which started some six perhaps even seven thousand years ago with the beginning of agriculture, will be over forever. We know that the world population will grow and probably peak at 8 billion in 2030. This means that food production will need to increase by about 60 per cent. We also know that nearly all of that increase has to come from developing countries and from the intensification of agriculture, i.e. more yield per unit time and per unit area.

The demand for food will increase disproportionately to the increase in population. Rising incomes will mean a disproportionately higher demand for food to make up for malnutrition today and accommodate a shift in diets. Apart from vegetables and fruits, the most remarkable shift will be towards higher consumption of animal products, partly from monogastrics-from pigs and poultry. This will mean increased production of feed. The cereal market for feed will grow fastest and it is the only one which will have at least a noticeable impact on world market prices.

Urbanization will continue. In 1950, two thirds of the world population lived in rural areas; in 2030 or even before that, two thirds of the world population will live in urban areas. This means lower labour availability in rural areas. It will undoubtedly imply new forms of mechanization. Labour use efficiency is another very clear trend; therefore, land use intensification, in all of its connotations, is one of the things we do not doubt.

It is likely that agriculture will have other dimensions beyond food and fibre production, such as its role in carbon sequestration and in preserving landscapes, watersheds and biodiversity. There are exciting developments in the nutripharmaceutical and food quality sectors that may impact on future agriculture. These other dimensions are less clear, and I would put them more in a category of what we guess, rather than what we know. Nevertheless, it is sure that we will look at agriculture as something beyond just producing calories per hectare in 2030.

On increasing efficiency in fertilizer use
There is tremendous scope for improvement in efficiencies as long as we remember what I was told when I was a student: "Don't fertilize the soil, fertilize the plant". Higher crop yields mean higher fertilizer use, but not proportionally. An entire system of supply, research, extension, quality control inputs, etc. ensures that farmers are realizing these efficiencies. In Asia and other parts of the world, these increases are not very strong, but they also exist. I hope that more efficient fertilizer use will match the growth in production-I say "hope" because there are some parts of the world where this hope, particularly in Africa, is not realized today.

In 1950, farmers applied only 17 million tonnes of mineral fertilizers. That was four times more than in 1900, but eight times less than today. When we look at northern Europe, fertilizer use has increased from about 45 kg/ha to 250 kg/ha. Wheat yield in France, for instance, increased every year from about 1,800 kg/ha in the 1950s to more than 7,000 kg/ha today. Again, we see overall patterns of efficiency in fertilizer use; the increase in use certainly is lower than the increase in yields. So far, so good. On the loamy soils of Northern Europe, we now get yields that are over 10 tonnes/ha, very close to the present biological maximum, and are obtained with only 200 kg of nitrogen and 50 kg of phosphate and potassium, respectively. The potential to improve fertilizer use efficiencies is thus tremendous.

On the need to increase fertilizer use
Fertilizer application contributes 43 per cent of the 70 million tonnes of the nutrients that global crop production extracts. In the future, the contribution may be as high as 84 per cent; that means the world's agriculture will become more and more dependent on mineral fertilizer. We do not know exactly whether crops will indeed remove more than 207 million tonnes in 2015 and even more in 2030. But we do know that the increase of fertilizer as part of the total nutrient cycle will be important. This has serious consequences for the way we look at the fertilizer industry and how we manage sustainable fertilization.

The question is, "how much will fertilizer use increase?" Even a 1-per-cent increase between now and 2030 would be a considerable one. In some parts of the world, we need a much larger increase-up to 2.7 per cent, and more in Africa, annually-to make up for nutrient losses. We still know little about trace elements and micronutrients in a systematic fashion or in terms of global cycles. This area must be looked at with priority if we want balanced nutrient management.

The public often thinks that non-mineral nutrient resources are a major source also for the future. However, their efficiencies are considerably lower. There will be more manure available with increased livestock production. Moreover, urbanization means more waste, especially more sewage waste. The current cost of using waste for crops is still quite high. Maybe some of these costs will reduce, but fertilizer will remain the most important source of added nutrients.

On the limits of organic agriculture for food security
We should develop a clear, scientifically-based view of what organic agriculture can mean in terms of world food security. We know relatively little about the scope for organic agriculture-a subject that is so dear to some sectors of the Western society and often such a source of confusion. At FAO, we have done some very tentative calculations about what organic agriculture would mean on a global scale if indeed the market would demand a very substantial increase in organic agriculture. The consequences are quite staggering, considering the amount of land that would have to be brought under rotation with legumes or under animal production to make up for farmers not using mineral fertilizer. It seems quite unfeasible. While organic agriculture provides a niche market, the limits of organic agriculture and its danger in terms of nutrient depletion need thorough review. Not just in OECD countries but increasingly also in developing countries, the public needs objective information on the potential of organic agriculture.

Fertilizers are irreplaceable, particularly in Africa with its specific soils. That is the message that has to be put across to students, as well as the general public. Probably one of the most destructive systems in terms of environmental damage is unfertilized annual cropping in the humid tropics, with its high impact on soil organic matter and erosion. We need to look at systems in a much more integrated way. Such an approach to nutrient management is really important and should move the discussion away from talking about fertilizers in the narrow sense of the word.

On the potential of biotechnology for food security
The basis of the Green Revolution was crop varieties with improved responses to nutrients and water. Since then, while there is considerable interest in biotechnology, not so much yet is heard about biotechnology and fertilizers. We should ask ourselves-and this we really still do not know-"Is there a possibility of improving fertilizer use and plant nutrient uptake efficiency through biotechnology?" Hardly any current work in biotechnology addresses abiotic stresses or biological nitrogen fixation.

But we should not focus too much on biotechnology. There is still a lot to gain with conventional plant breeding. Considerable work has been done on the so-called "staying green" characteristics of a crop like sorghum, as the longer the crop stays green, the more fertilizer uptake there can be over time. So while we should not underrate the longer-term potential of biotechnology, I also feel that we should be very careful in promising too much, too quickly. Possibly, the conventional breeding work on aluminium and iron toxicity has applications also for biotechnology.

Soil biology is another area where we know very little and should know more. It's still a rather isolated field of research and does not always link very well with nutrient management. We certainly know that soil organic matter and soil biology are important, but we do not have very good tools to monitor that. We also know, of course, that nutrient recovery for fertilizer is much better with soil improvement. However, much is still unclear in practical terms.

In Africa, where the recovery of nutrients is so low, more systematical work is needed on soil organic matter and soil quality in a physical, biological and chemical way. Biological nitrogen fixation yields mixed results. It is clear that we need to look at it again in an integrated manner, linking biological nitrogen fixation to the application of more conventional fertilizers and study recovery. It would be necessary to have clearer evidence on this, and again to communicate that to the public, in order to show that biological nitrogen fixation is not a miracle solution by itself, but may be successful under certain conditions. There is interesting cereal-legume rotations work that perhaps deserves more systematic application. Such work links with water use efficiencies, dry land agriculture and water harvesting, and needs again a comprehensive review.

On integrated management of production systems
We have made advances in integrated management of production systems. Conservation agriculture, for example, clearly yields results and clearly allows us to reduce stresses on the environment with respect to run-off and erosion. So again we should look at the whole production system, rather than just the nutrient part of it.

I have said there is a growth in waste material and manure as we go on toward 2030 and have pointed to the importance of micronutrients and trace elements. However, at the current level of knowledge, how much we can do-with P fixation or with nitrogen fixation-is still very unclear. Developed countries' use maybe 20 per cent of all treated sludge in agriculture, and perhaps it will be only 5 per cent in the near future in developing countries. These are not enormous numbers, but it could very well be that increased urbanization puts such stress on waste management that because of environmental health issues we are forced to deal with waste in a much better way. This would again be an impetus for integrated nutrient management worldwide.

On the implications of the World Food Summit
At the World Food Summit in 1996, Governments committed themselves to halving the number of hungry people by the year 2015. There is a direct link between that goal and fertilizer use. This could mean about 8 per cent more fertilizer use with respect to a business-as-usual scenario. It does not seem like very much, but in terms of tonnage it is considerable. The enhanced fertilizer use is particularly important in countries like China and India, which make up a large proportion of the world population and play a major role in meeting those goals, but even more so perhaps in Africa, where little progress has been made. From a global perspective, there have been modest shifts in terms of which populations are at risk of starvation; however, in Africa the general situation remains very bleak.

We can learn in this respect from the work on pesticides. There have been quite remarkable results in reducing pesticide applications by making farmers more aware of integrated pest management through a system called farmer field schools, where they learn to observe their crops closely and discuss the management of pests or the pathogens and their predators. Those projects are increasingly linked to integrated nutrient management, and this is a very promising approach. It would require farmers to observe better the impact of nutrient application, rather than letting them apply more urea just because it's the cheapest fertilizer and thus creating a risk of over-application.

On educating farmers on nutrient management
We need to see how we can help farmers understand the effects of overuse of nitrogen on certain pathogens and other stress factors in crops. This may convince farmers of the need to free up money to buy non-nitrogen fertilizer and adopt a much more balanced fertilizer application. Farmers will also need help with investing in better water use, water management and water capture. We are talking about a comprehensive package.

The real risk is to think that fertilizer is the one and only solution to productivity increase. We really stand to gain from such integrated agro-ecological management. History shows us that the gains of nutrient use are tremendous. There is a curve of diminishing returns that we need to manage very carefully. An increase of end-use efficiency, even from 40 to 50 per cent, could make considerable savings for farmers, as well as in the transport industry, and in the way poor countries use scarce foreign currency on fertilizers.

UN photo

On developing partnerships for food security
Fertilizer-use efficiency is the challenge of the future. The gains of such efficiency, even purely economically, may be tremendous. However, we will not have these gains if we do not work on the entire set of factors that determine fertilizer-use and its application by farmers. We need private/public partnerships. We need a much better system of distribution and quality control, and the array of marketing that goes with it.

The fertilizer industry should become more creative in ensuring that a farmer actually gets the maximum benefit out of the existing crop and fertilizer application techniques. I really hope that the industry will also look at the total cycle of nutrient use and nutrient recovery. Let's systematically look at key ways to reduce labour demands, which is particularly important with decreasing labour availability. For example, there are now polymer-coated fertilizers that could have a much better recovery rate. I know they are expensive, but let us not forget that the first computers and the first colour televisions were also incredibly expensive and now have reached many households in the poorer world. The car manufacturing industry received the same plea twenty years ago and has made considerable progress.

We know that there is still a lot of misunderstanding and confusion about nutrients in the world. The public needs to obtain an objective image and an objective message from all the partners involved in nutrient management. Governments, industries, NGOs, farmers, and international organizations and FAO must make sure we develop a balanced objective and science-based, evidence-based message about the use of fertilizers, their potential and their limitations, and the need to look at them in a comprehensive context. We know about the productivity gains that are possible and that fertilizer-use efficiencies are possible if we do it the right way. We know that more fertilizers are needed.