Gypsiferous soils are extensive and occupy about 85 million ha in Spain, USSR, Argentina, Australia, Iraq, Tunisia, Algeria, Libya, Syria and Somalia, among other countries. They are found mainly in arid and semi-arid zones with less than 400 mm of annual rainfall. Gypsiferous soils are usually found in the middle and lower parts of the landscape and have a potential for agricultural development under both rainfed and irrigated farming.
In many zones of the arid and semi-arid regions, gypsiferous soils coincide with densely populated areas where irrigated agriculture is necessary if food, fibre and other agricultural raw materials are to be produced for the livelihood of the population. Various factors such as low fertility, small water retention capacity, shallow depth to a hardpan, vertical crusting and the salinity of these soils limit their intensive use. The formation of sink holes associated with the installation of drainage and irrigation systems is a hazard which could be countered after careful study and knowledge of the physical and chemical characteristics of these soils.
Gypsiferous soils have received rather limited attention from soil scientists, in spite of their importance for, and problems in, agricultural development. This Bulletin aims to summarize and update our knowledge of the origin and classification of gypsiferous soils, of their physical and chemical characteristics, fertility status and ways of improving their productivity. The Bulletin is intended to serve soil scientists, agronomists, extension workers and agricultural students. Indirectly, it should thus serve farmers on gypsiferous soils and policy makers proposing agricultural development.
The original manuscript for this publication was prepared by Dr A. Matar of ICARDA and Dr Osman of ACSAD. It is through the efforts of these scientists that a new awareness of the potentials of these soils is once again highlighted. The manuscript was revised and completed by Dr A. Sayegh of FAO and Dr T. Boyadgiev of the Poushkarov Institute, Bulgaria. The script was finally edited for publication by J.M. Hodgson and P.J. Loveland of the Soil Survey and Land Research Centre, Silsoe, England. FAO gratefully acknowledges the contributions of all contributors to this volume.
For editorial reasons, some traditional non-SI units were retained in this volume. Appendix 5 contains conversion factors to SI units.
If new information warrants it, a revised edition may be issued in a few years' time. Relevant material and reprints are solicited and may be sent to R. Brinkman, Chief, Soil Resources, Management and Conservation Service, FAO, Via delle Terme di Caracalla, 00100 Rome, Italy.
