Salinity management in the coastal region of the Netherlands: A historical perspective

• Review of history of salinization and desalinization in the Netherlands.
• Reclamation projects in response to storm floods and strategic wartime inundations.
• Role gypsum in Na–Ca exchange and in acid sulfate soils.
• Early physico-mathematical models of salinization, desalinization, cation exchange.
• Early studies of crop tolerance/intolerance to salinity.

In coastal regions of the Netherlands, various aspects of salinity were recognized and dealt with throughout history: causes of salinization and sodification, desalinization, soil structure deterioration and rehabilitation, crop salt tolerance/intolerance, and soil and crop management. Originally, experience of water managers and farmers formed the basis. From 1850 onward, first mainly chemical analysis, later combined with physico-chemical concepts, and still later also analyses of flow and transport processes, and plant physiology were used to transform traditional opinions into scientific understanding. In the 20th century, salinization and sodification arose from natural floods (1906, 1916, 1953) and strategic wartime inundations (1939/1940, 1944/1945), and in the context of creation of the Zuiderzee Works and the Delta Works. J.M. van Bemmelen (1830–1911) pioneered diagnosis of salinity and the study of acid sulfate soils, while D.J. Hissink (1874–1956) understood sodicity and promoted application of gypsum. These early studies were amplified, respectively, by C. Nobel and S. Smeding on monitoring salinity, by A.J. Zuur and B. Verhoeven on desalinization, by W.H. van der Molen and G.H. Bolt on ion exchange, and by K. Zijlstra and C. van den Berg on salinity tolerance/intolerance. In the period 1923–1940, the civil engineer J.P. Mazure studied seepage from saline open water into lower lying land and diffusion and convection of salts into and out of lake bottoms.