1. The Consultation considering the high investment involved in land reclamation and irrigation projects and the seriousness of possible failure of such projects and, recognizing that protection is better than cure, felt that proper planning should be based on:
a. sound economic and social justifications, not only on a short term basis but also on a long term one;2. The Consultation recognized the importance of prognosis of salinity and alkalinity which should be based on knowledge of processes involved, and realizing the necessity of achieving and maintaining favourable salt balance and the value of early prediction of potential hazards, considered that measures should be taken to monitor regularly salinity and alkalinity changes by testing:b. investigations on soils, hydrology, hydrogeology, topography, vegetation, climate, groundwater depth and quality, artesian water, irrigation water quality and quantity and crops;
c. surveys that are carried out regarding the land properties related to salt and water movement;
d. suitability of the land for development, not only within the project boundaries but as part of the surrounding land characteristics or the watershed area;
e. efficient management that is formulated in terms of specific environmental conditions.
salt concentration and composition of the soil, irrigation and groundwater quality, depth to groundwater, water transmitting properties of the soil, environmental factors affecting evapotranspiration, crop performance and yield.Also consideration should be given to using proper water management practices to push salts below the active root tone, to adequate drainage systems being provided and to desalination of the groundwater being maintained, especially where conditions become favourable for upward water movement and evaporation. Care must be taken in land levelling and other cultivation techniques, including mulching and fallowing. It was stressed that crop rotations should be considered not only in terms of their economic return, but also in terms of the suitability of crops in connection with soil and water qualities and their effect on the salt balance.
3. The Consultation took note of the new developments in the field of methodology, such as remote sensing, modelling and soil resistance measurements that facilitate the process of prognosis and monitoring. They also felt that related equipment and procedures for verification needed to be developed further. The use of the soil conductivity measurement technique was considered to be of particular interest.
4. It appeared to the Consultation that a considerable gap still exists between the basic principles available in the fields of soil and water sciences and their application to solve problems of salt affected soils. This gap was recognized to be due to inefficient application of existing sound practices or to the delay in dissemination of available knowledge. It was felt, therefore, that extension services in soil and water management should, be strengthened and that training, at various levels from planners to farmers, be stressed in the theoretical and practical aspects of causes, diagnosis, monitoring and remedies of salinity and alkalinity.
5. The discussion daring the Consultation reflected the general agreement on the main factors and processes affecting salinity and alkalinity but there was a difference in views on the relative weight of some of those factors and in the methodology of prognosis. These differences in approach were due to different types of management systems. In order to make specific recommendations, avoiding risks of over generalization, it was suggested that research stations and institutes continue or initiate investigations on quantification of the various parameters of the salt balance appropriate to a regional condition. It was also felt that new methodology, such as remote sensing, should be evaluated for prognosis and monitoring of salinity and alkalinity and that modelling could serve as a tool in securing better management of irrigated lands and, therefore, its practical application should be verified under field conditions. The discussion on the methods of assessment of water quality for irrigation stressed that water quality criteria should be adapted to specific conditions.
