What is Salinity?
Photo Credit: https://www.ag.ndsu.edu/publications/crops/managing-saline-soils-in-north-dakota
Soil salinity is caused by excessive levels of water soluble salts in the soil water. Soluble salts are a combination of positively and negatively charged ions such as table salt (Na+Cl–). Salts directly affect plants as high levels of ions (positive and negative) from soluble salts restrict normal water uptake by plant roots, even when soils are visibly wet, resulting in drought-stressed plants (osmotic effect). Often clear visual symptoms of salinity can be seen at the soil surface in form of salt crust as once the water content becomes less than the solubility of the salts, the ions recrystallize and can be seen as “salts” on the soil surface or within the soil profile. In addition to competing with plants for water, certain salts for example Na+Cl– can also cause ion imbalance and toxicity in plant cells. Soil salinity levels are measured in field or by sampling the affected areas and getting them analyzed by a soil lab for Electrical Conductivity (EC). It is important to note that salts do not cause deterioration of soil structure. In fact, if calcium (Ca2+)-based salts are dominant, Ca2+ ions encourage aggregation of soil particles called flocculation (clumping together), resulting in well-defined pores facilitating free water movement through the soil profile.
Do you have an excellent resource that isn’t listed here? Submit it for consideration.
| Title | Source | Resource type and Date | Short Summary / Preview |
|---|---|---|---|
| Saline and Sodic Soils Part 1 | North Dakota State University | Video
Dec 2013 |
This two-part video explain soil salinity, sodicity, how they affect plants and soils and the reasons, which cause both of these issues in North Dakota. |
| Saline and Sodic Soils Part 2 | North Dakota State University | Video
Dec 2013 |
This video talks about the common symptoms of soil salinity, sodicity, the importance of sampling the affected areas, and remedial options. |
| Managing Saline Soils in North Dakota | North Dakota State University | Extension Publication
Sep 2019 |
This publication talks about testing your soil, salinity management, mapping, crop selection and tile drainage. |
| Managing Saline Soils in North Dakota | North Dakota State University | Extension Publication
Sep 2019 |
This publication talks about testing your soil, salinity management, mapping, crop selection and tile drainage. |
| What is the Difference between Saline and Sodic soils? | North Dakota State University | Extension Webpage
Not Dated |
Soluble salts are produced by the weathering of geologic materials in the soil and have been naturally distributed throughout the profile as soils developed. These salts have continued to move throughout the soil profile based on climatic patterns and management practices. |
| Management of Saline and Sodic Soils |
Kansas State University | Extension Publication
Sep 2017 |
Salt-affected soils can severely reduce land value and productivity. Soil tests can determine if salt accumulation is a problem. Problems include high total salts (saline soils), excess exchangeable sodium (sodic soils), or both (saline-sodic soils). These soil conditions can severely affect crop growth. Crops react differently to salt-affected soils. Soil reclamation is possible but not always economically feasible. |
| Saline and Sodic Soils | North Dakota State University | Extension Fact Sheet
Not Dated |
The wet climate during the last 20 years has increased salinity acres. As per a recently published report there are nearly 5.8 million acres in North Dakota which are affected by soil salinity. With more acres affected each year by salinity and sodicity, the management and alleviation of saline and sodic soils cannot be stressed more. |
| Remediation of Sodic (Alkali) and Saline Soils | SARE | Online Book Section
2007 |
The amount of extra irrigation water needed to leach salts is also related to the sensitivity of the plants that you’re growing. |
| Salinity and Sodicity in North Dakota Soils | North Dakota State University | Extension Publication
May 2000 |
This publication explains the differences in soil salinity versus sodicity, their effects on soils and plants, general salinity thresholds for yield reductions and crop symptoms, common causes, plant indicators and detailed recommendations for remediation. |
| Soil Testing Unproductive Areas | North Dakota State University | Extension Publication
Jun 2016 |
This publication outlines the differentiation of salinity versus sodicity, their negative effects, sampling the affected areas, lab tests required to assess the levels of salinity and sodicity, differences in the testing methods and brief interpretation of the lab analysis results. |
| Title | Source | Resource type and date | Short Summary |
|---|---|---|---|
| Reclaiming Saline, Sodic, and Saline-Sodic Soils | University of California | Fact Sheet
Aug 2015 |
This publication explains soil salinity, sodicity, their effects on crop production and water and air movement through the soils along with the remedial practices including the calculation of the amendment rates per acre to remediate sodicity. |
| Add-on Test: Salinity | Cornell | Extension Fact Sheet
May 2017 |
Although salinity and sodicity are often mistaken as the same thing, they are in fact quite different from each other. We include the comparison between salinity and sodicity here for clarification – Problems with salts (salinity) and sodium (sodicity) may occur naturally, but are especially prevalent under irrigated agriculture. |
| Basics of Salinity and Sodicity Effects on Soil Physical Properties | Montana State University | University Webpage
2003 |
Saline irrigation water contains dissolved substances known as salts. In much of the arid and semi-arid United States (including Montana), most of the salts present in irrigation water are chlorides, sulfates, carbonates, and bicarbonates of calcium magnesium, sodium, and potassium. While salinity can improve soil structure, it can also negatively affect plant growth and crop yields. |
| Soil Salinity Testing, Data Interpretation and Recommendations | University of Georgia | Extension Publication
Oct 2015 |
Soil salinity is caused by several factors. Soils may become saline as a result of land use, including the use of irrigation water with high levels of salt. |
| Title | Source | Resource type and date | Short Summary |
|---|---|---|---|
| Comparison of 1:1 and 1:2 Suspensions and Extracts with the Saturation Extract in Estimating Salinity in Saskatchewan Soils | Canadian Journal of Soil Science | Peer-reviewed Publication
1984 |
This publication discusses different methods that estimate soil EC, variations in results due to the methods and conversions based on soil texture. |
| Diagnosis and Improvement of Saline and Alkali Soils | USDA | Handbook
Feb 1954 |
This is one of the most comprehensive handbooks on laboratory procedures for measuring soil properties related to soil salinity and sodicity put together by the United States Salinity Laboratory Staff. |
| Problems in Production Fields – Saline and Sodic Soils | Soil Science Step‐by‐Step Field Analysis | Peer-reviewed publication
Sep 2008 |
This book chapter describes soil salinity and sodicity, identifying these issues and outlining traditional and alternative management practices for remediation. |
| Reclamation of Salt-Affected Soils | Agricultural Drainage | Peer-reviewed publication
Jan 1999 |
This publication extensively explains effects of salinity and sodicity on soil chemical and physical properties and reclamation of saline and sodic soils under tillage, crops and irrigation systems and by using soil amendments. |
| Soil Salinity Using Saturated Paste and 1:1 Soil and Water Extracts | Soil Science Society of America Journal | Peer-reviewed publication
Jun 2005 |
This publication discusses the correlation between the most common method to measure soil EC (1:1 Soil:to:Water) versus the more time consuming method, saturated paste extract. |
| Dryland Salinity: Soil Processes and Management | Annals of Arid Zone | Peer-reviewed publication
2006 |
This Australian publication talks about the causes of soil salinity under dryland agriculture and its effects on agriculture production.
Note: This links to an abstract of the article. You may need to contact your library to request a copy of this article as a free electronic version is not available. |
Technical review: March 31, 2020