IAEA, Vienna, 2003. – 78 p. (Анг. язык)
IAEA TRAINING COURSE SERIES No. 16, Second EditionWater is an essential requirement for life on the planet. It is often the single most limiting factor in crop and livestock production. Water is a scarce resource in many urban and rural environments worldwide. According to the FAO, the global demand for fresh water is doubling every 21 years. The quality of the finite water supplies is also under threat from industrial, agricultural and domestic sources of pollution.
The majority of crops are grown under rain-fed conditions and adequate water supply is the main factor limiting crop production in semi-arid and sub-humid regions. On the other hand, currently 20% of the world’s arable land is under irrigation providing 35 to 40% of all agricultural production. Irrigation mismanagement poses a serious threat to the environment through groundwater pollution and salinization. It is therefore, essential that water resources be used efficiently by regular monitoring of soil-water status in the unsaturated zone. The neutron depth probe, a nuclear-based technique, is utilized worldwide for this purpose. The neutron moisture gauge, since its introduction some 40 years ago, can now be considered a routine method in soil water studies. Many developments have since been introduced, in particular electronic components, which have significantly improved performance and expanded applications. Although the neutron scattering method is routinely utilised in many developed countries, its use is still limited in developing countries due to several factors. Neutron depth probes contain radioactive sources, which will present health and environmental hazards if a probe is improperly used, stored or disposed of. National and international legislation and regulations must be complied with.
The strategic objective of the sub-program Soil and Water Management & Crop Nutrition of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture is to develop and promote the adoption of nuclear-based technologies for optimising soil, water and nutrient management within cropping systems. In this context, neutron moisture probes in combination with isotope techniques are utilized to obtain precise and quantitative data on water and nutrient dynamics in the soil-plant system.
The Centre for Nuclear Techniques in Agriculture (CENA) of the University of Sao Paulo, Piracicaba, Brazil is an institute established with IAEA support, with skilled and experienced staff and facilities to utilize nuclear techniques in agronomic and related environmental research. Many training events and formal undergraduate and post-graduate courses involving the use of neutron moisture meters have been offered by CENA. The concept of a training manual originated during a regional training workshop on the use of the neutron probe in water and nutrient balance studies, organized in 1997 in the frame of an IAEA Regional Technical Co-operation Project for Latin America entitled Plant Nutrition, Water and Soil Management (RLA/5/036-ARCAL XXII), for which the integrated approach was adopted. The original version (in Spanish) was a comprehensive manual covering theoretical and practical aspects required for the proper utilization of the equipment. The contributions of the peer reviewers, editors and technical translators of the three versions in English, French and Spanish have greatly enhanced the content and quality of the manual. Their assistance and dedication is highly appreciated.
It is hoped that this manual will be useful for future training events and serve as a key reference to soil/water scientists in the field of sustainable management of scarce water resources in both rain-fed and irrigated agricultural production systems.
