Coping with soil and water salinity for crop production in Algeria: A continuing effort of integrated land-water management approach
In Algeria desertification is putting extreme stress on irrigated agriculture due to the fast rate of soil and water salinization, resulting in the drastic reduction of arable land with productive agricultural potential. This phenomenon is most notable in the Western part of the country where major irrigation schemes are located. Out of a total area of 140,000 hectares in this part of Algeria, 30% consists of very saline soils (Electrical Conductivity (EC), a measure of salinity of over 8 deci Siemens m-1).
The situation is exacerbated due to the shortage of good quality water (EC<2 dS m-1) for irrigation which currently supplies only 10% of the water required. This is because the quality of large aquifers (quaternary sediments) groundwater is generally of poor quality with an average EC of 4.5 dS m-1 and a median Sodium Adsorption Ratio (SAR) of 20, which made them classified as being very high hazard of salinization and sodium alkalization. In recent years, due to the high salinity, farmers have abandoned these lands. The objective of this project on Nuclear Techniques for Sustainable Use of Saline Groundwater and Wastelands for Plant Production aims to reduce salinity induced land degradation through developing appropriate irrigation, drainage, soil and crop management practices so that preventive and corrective measures of salt-affected agricultural lands can be established. In addition, databases and reference baseline works of the hydro-saline conditions in the main agro-ecological zones in Algeria can also be established.
The study was carried out by the Institut National du Sol, Irrigation et Drainage (INSID) in the Wilaya of Relizane, one of the five main irrigated schemes in Western Algeria. Deep tillage ploughing in late summer was carried out to increase infiltration capacity and water retention in soil. Similarly drainage system has been installed to provide leaching of salt beyond crop rooting zone. At the same time, three moderately salt tolerance crop species (olives, barley and oats) which can tolerate to a soil salinity of 8 dS m-1 were irrigated with irrigation water of 5 dS m-1 to test their performance under these harsh conditions. Since the implementation of the project, some farmers near the study site have returned to cultivate barley on their lands using the same approach. It is hoped that through this project, an integrated approach to plant, soil and water management practices (identification of salt-tolerant plants of economic value, development of irrigation and drainage technology packages for using saline soils and groundwater) would be adopted.
The project aims to disseminate the knowledge of sustainable use of saline lands and brackish water of using salt tolerance trees and crops in arid lands to improve the environment and produce a biomass that will be useful as food for livestock, fodder, wood fuel, fertilizer, and agrifood.