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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 2/15/2017 Publication Date: 8/21/2017 Citation: Corwin, D.L., Yemoto, K.K. 2017. Salinity: Electrical conductivity and total dissolved solids. In: Nilsson, M., Hmielowski, T., editors. Methods of Soil Analysis. 2nd volume. Madison, WI:Soil Science Society of America. p. 1-16. Interpretive Summary: The accumulation of salinity in the soil root zone can have adverse effects on crop yields by making it more difficult for plants to obtain water, upsetting the nutritional balance of plants or causing toxicity by a specific ion (e.g., sodium), and by affecting physical properties of soils (e.g., tilth and permeability) that influence plant growth. Because of the potential detrimental impacts of soil salinity accumulation, it is a crucial soil chemical property to measure and monitor. The objective of this chapter in SSSA Methods of Soil Analysis is to provide a thorough discussion of the measurement of soil salinity at scales of < 200 m3 with focus on the measurement of soil salinity in the laboratory using electrical conductivity of aqueous extracts from soil samples and measurement of total dissolved solids in the saturated soil extract. Discussion is also given to the use of suction cup extractors, porous matrix/salinity sensors, electrical resistivity, and electromagnetic induction to measure salinity in soil lysimeter columns and small field plots (< 10 x 10 m). The chapter provides a basic knowledge of the background, principles, equipment, and current accepted procedures and methodology for measuring soil salinity. The information presented is sufficient to guide undergraduate and graduate students, university faculty and staff, post-graduate rersearchers, soil scientists, agricultural engineers, resource specialists, agronomists, plant scientists, and agricultural consultants in applying the techniques available for measuring and monitoring soil salinity at scales of small field plots or less, whether to meet research objectives or real-world applications. Technical Abstract: The measurement of soil salinity is a quantification of the total salts present in the liquid portion of the soil. Soil salinity is important in agriculture because salinity reduces crop yields by reducing the osmotic potential making it more difficult for the plant to extract water, by causing specific-ion toxicity, by upsetting the nutritional balance of plants, and by affecting the tilth permeability of a soil. A discussion of the principles, methods, and equipment for measuring soil salinity is presented. The discussion provides a basic knowledge of the background, principles, equipment, and current accepted procedures and methodology for measuring soil salinity in the laboratory using electrical conductivity of aqueous extracts from soil samples and measurement of total dissolved solids in the saturated soil extract. Discussion is also given to the use of suction cup extractors, porous matrix/salinity sensors, electrical resistivity, and electromagnetic induction to measure salinity in soil lysimeter columns and small field plots (< 10 x 10 m). Land resource managers, producers, extension specialists, Natural Resource Conservation Service field staff, undergraduate and graduate students, and university, federal, and state researchers are the beneficiaries of the information provided. |
