Review of crop salt tolerance in the Netherlands

Supportive irrigation is practiced in the Netherlands to overcome drought spells in the summer season. In the south-west delta mainly surface water is used of which the salinity is likely to increase. This study investigates the effects of saline irrigation on potatoes, sugar beet, grass, and tulips for different soils using a modeling approach. A comparison was made with a previous study showing the importance of climate and soils on crop reaction when applying supportive irrigation with variable salinities. It was found that the internationally accepted concept of Maas and Hoffman to estimate crop damage due to salts is not sufficiently reliable to establish salinity norms under conditions prevailing in the Netherlands. Recommendations are given for trade-offs between drought and salt damage, modeling improvements, and experimental field research.