Korean Journal of Soil Science and Fertilizer ISSN:0367-6315(Print) 2288-2162(Online) 한국토양비료학회 학회지

While electrical conductivity (EC) and sodium adsorption ratio are commonly used to assess soil salinity, for detecting salinity responses during a growing season, those indicators appear to be insensitive when the soils are already high in salinity. We found that the EC and chloride concentrations in soil extracts from salt-affected greenhouses did not show a significant difference in response to different fertilizations of tomato (with a high N demand and a low susceptibility to salinity) and lettuce (the opposite) over the growing season. The fields had been treated with chemical fertilizers or chemical fertilizers plus manure composts combined with food wastes to investigate salinity enhancement by the amendments. On the other hand, the regression lines between EC and chloride concentration could show differential responses in both soil and plant extracts to the doses and salinities of fertilizers. Therefore, using the relationships between EC and associated ions can provide a better insight into the salinity susceptibilities of soils and plants.

Relationship between EC and chloride concentration in plant extracts: (a) comparison between tomato and lettuce fields fertilized with chemical fertilizers, (b) comparison between tomato and lettuce fields fertilized with food-waste combined manure compost. The p value represents the significance of the difference between the slopes.