Micronutrients and the nutrient status of soils: a global study [antikvár]

Ill Foreword During the last two decades, the increasing use of mineral fertilizers and organic manures of different types has led to impressive yield increases in developing countries. Major emphasis was given to the supply of the main macronutrients, nitrogen, phosphate and potash. For a long time it was felt that under the existing farming systems and fertilizing practices the level of micronutrients was adequate and that the problem of micronutrient deficiencies was not a serious one. However, indications from developing countries show that micronutrient problems are becoming more and more frequent. In the early 1970s the Government of Finland, through its Institute of Soil Science and FAO embarked on a system of investigation of microelement deficiencies in developing countries. In 1974, the project "Trace Element Study, TF/129/FIN" started under the FAO/ Finland Cooperative Programme, with the financial support of the Government of Finland, and with the cooperation of the staff of the Institute of Soil Science, under the direction of Prof M. Sillanpaa. The facilities of the Institute were made available to the project. This programme involved a worldwide study on micronutrients, in cooperation with 30 countries. The study, which is presented in this document, shows that the undertaking was very timely. It appears that micronutrients are becoming deficient in developing countries and that remedial measuring will need to be taken to ensure full soil and plant productivity. The study also gives guidance for the investigation of micronutrient deficiencies, which should be dealt with at the country level. FAO expresses its appreciation to the Government of Finland for its generous support of the study and for its excellent cooperation throughout. F.W. Hauck Chief, Soil Resources, Management and Conservation Service