Preface

This document aims to present a balanced view of, on the one hand, the benefits of using mineral fertilizers and on the other hand the environmental risks involved. It is not intended to be a scientific document, but it aims to be technically correct.

Chapter 14 of Agenda 21, agreed at the UNCED “Earth Summit” held in Brazil in 1992, states “The world's capacity to feed a growing population is uncertain agriculture has to meet the challenge mainly by increasing food production on land that is already in use, and avoid encroachment on land that is only marginally suitable for cultivation”.

This review presents the evidence supporting the view that the use of mineral fertilizers is a necessary condition for achieving these objectives. Their use is necessary but they do have an impact on the soil, water, air, plant and human health.

All human activities affect the natural environment either adversely or beneficially, and what is adverse or beneficial may depend on one's point of view. The long-term sustainability of any system requires complicated trade-offs between benefits and losses. Almost always, there are ways of minimizing losses while retaining benefits. The use of fertilizers is no exception, but both the policy maker and the farmer must have the necessary knowledge. Farmers must know how to use fertilizers efficiently under their own particular circumstances. Most of the adverse effects of fertilizer use result from inadequate knowledge among farmers.

The review highlights the importance of using mineral fertilizers efficiently. Inefficient use not only increases their negative environmental impact unnecessarily, but also represents a large waste of natural resources and a substantial economic loss.

To improve the efficiency of fertilizer use is a major challenge. There is also scope for improved products, but the greatest medium-term gain could be had from improving the way in which currently available fertilizers are used. Many techniques for achieving this are known, but often they are not put into practice. The task of communicating information on the correct techniques to farmers, and of persuading them to adopt them, is formidable. Of the world population of 5.7 billion in 1995, the agricultural population accounted for 2.6 billion.