Lately, I’ve been contacted by several growers regarding the same issue: stunted crops, white crusts on the soil, and irrigation water sitting on the surface. After reviewing their soil test results and visiting two of their fields, it became clear that salt buildup was the underlying issue. If you're seeing these signs, this guide will help you understand what may be happening and walk you through steps to protect your soil and crops.

Start here: What kind of salt problem do you have? 

These problems are common in arid climates and are often mistaken for drought or nutrient deficiencies. However, not all salt-affected soils are the same. Knowing which kind you’re dealing with is the first step.

Saline soils, also known as “white alkali,” contain high levels of soluble salts (calcium and magnesium) that increase the osmotic pressure in the soil water. This makes it difficult for roots to absorb water, even when the soil appears moist. Your plants may look like they’re drought-stressed, wilting, stunted, or showing burned leaf edges even though there’s moisture in the soil. Salts can also interfere with nutrient uptake, making plants appear nutrient-deficient. Salinity usually builds up when salty irrigation water is used and there’s not enough drainage or rainfall to flush the salts out.

Sodic soils, also known as “black alkali” or “slick spots,” are dominated by sodium, which disrupts the natural balance of soil particles. Unlike calcium or magnesium, which help soil particles bind into stable aggregates, sodium causes particles, especially clay, to repel each other. This leads to the breakdown of soil structure, making the soil compacted and sealing the surface. As a result, water infiltration becomes very slow or completely blocked. You may notice crusting on the surface, a slick or greasy feel when wet, and standing water after irrigation. Over time, plant roots struggle to grow through the dense layers, oxygen levels drop, and crops show signs of stunted growth or uneven emergence.

Saline-sodic soils combine both problems of high salt levels and excess sodium. This means your plants are under osmotic stress and struggling to take up water, just like in saline soils, while also dealing with the structural damage caused by sodium, just like in sodic soils. As a grower, you’ll see both leaf burn and wilting, along with poor water infiltration, crusting, and compacted soil that roots can’t easily penetrate. These conditions make it especially difficult to establish crops and can severely limit yields if not managed with both chemical amendments and leaching.

How to know: Field observation and laboratory tests 

Don’t rely on appearances alone. While salt crusts may be visible, you won’t know the full story without a proper soil test. Here’s what to request when submitting soil samples for laboratory testing:

1. Electrical Conductivity (EC) – A measure of how much salt is present in soil or water, expressed in deciSiemens per meter (dS/m). Higher EC values indicate higher salt concentrations. Water EC (ECw) is the salinity level of your irrigation water. Higher ECw means more salt is being applied to your fields with each irrigation. While Soil EC (ECe) is the salinity level in the soil's root zone, measured from a saturated soil extract. This value helps determine how much salt your crops are exposed to and whether it's within their tolerance range.
2. Sodium Adsorption Ratio (SAR) – Indicates the amount of sodium relative to calcium and magnesium in soil water. High SAR levels suggest potential for soil structure breakdown.
3.  Exchangeable Sodium Percentage (ESP) – Reflects the proportion of sodium on the soil’s cation exchange sites. High ESP levels lead to poor soil physical properties, reducing water movement and root growth.

Use this guide to interpret your results:

**While pH is not the main indicator for salinity or sodicity, most crops do best in soils with a pH between 6.0 and 7.5.  These indicators work together to help you identify whether your soil is saline, sodic, or both, and what actions are most effective.

Where are the salts coming from? 

You might be adding them without knowing it. Salts can build up from:

1. Soil parent material
2. Irrigation water with even modest salinity
3. Heavy use of fertilizers, manures, or composts
4. Poor drainage or a shallow water table
5. Water softeners or nearby roads treated with salt

Irrigation water is often the most significant source of salt in farm fields. For instance, water with an ECw of 2 dS/m contains about 1.7 tons of dissolved salts per acre-foot. If you apply about 30 inches of this water annually, that adds up to roughly 4.4 tons of salt per acre each year. That’s a major load of salt entering your field annually, and if it isn’t leached out properly, it will keep accumulating in your root zone.

How salts impact your crops 

Salts increase the osmotic pressure in the soil solution, making it harder for plants to draw water into their roots. This means your crops can show signs of drought stress, wilting, stunted growth, or scorched leaf margins even when the soil appears moist. High salinity can also delay or prevent seed germination and reduce nutrient uptake. In sodic soils, excessive sodium breaks down soil aggregates, leading to poor structure and limited pore space. This reduces water infiltration and air movement, making it difficult for roots to grow and function properly. As a result, yield losses may occur before any visible symptoms appear.

What can you do about it?

Start with a water test: Always test the quality of your irrigation water. Salty or sodium-rich water will make matters worse. Ideally, irrigation water should have low salt (ECw) and sodium (SAR) levels to avoid contributing to soil salinity or sodicity. Work with your lab or our Extension office to interpret your test results and evaluate if your water is suitable for long-term use. 

Leach the salts if the problem is salinity: If your soil is saline (but not sodic), you’ll need to leach salts below the root zone by applying extra water. This is called leaching, and it’s most effective when done before planting or at the end of the season. Water is the preferred and most reliable method for leaching because it dissolves salts and moves them downward with infiltration. Note that drip irrigation, while efficient for routine watering, does not effectively leach salts without deliberate heavy water applications designed specifically for leaching.

Leaching is most successful when water can soak in and drain through the soil. If your soil is well-drained, you can apply clean irrigation water using either flood or sprinkler methods. For sandy or loamy soils, ponding 6 to 24 inches of water may be necessary to push salts below the root zone, depending on how much salt you need to remove, informed by your soil test results. On finer-textured soils (like clay), ponding smaller amounts multiple times, such as 2- to 6-inch applications, or using sprinkler irrigation helps reduce water use and improve effectiveness. Always allow time between applications for water to infiltrate. Reclamation won’t work without proper drainage, so be sure to address compacted layers, hardpans, or shallow water tables before leaching. Without drainage, even good water can turn your soil saline or sodic over time.

Fix sodic soils before you leach: If your soil test shows high SAR (>13) or ESP (>15), your soil is sodic and must be treated before leaching will be effective. Begin by applying gypsum (calcium sulfate), which supplies calcium to replace sodium on soil particles. This chemical exchange restores soil structure, improving water movement and root access.

The amount of gypsum needed depends on how much sodium you want to displace and how deep the treatment needs to go. For example, to reduce SAR from 14 to 8 in the top 2 feet of soil with a cation exchange capacity (CEC) of 10 and a bulk density of 1.4 g/cm³, you’ll need about 2 tons of gypsum per acre. Once gypsum is applied, follow with sufficient clean water to flush the displaced sodium below the root zone. If you skip the leaching, the sodium remains, and gypsum won’t be effective. Also, don’t use gypsum if your soil is saline but not sodic; it will only add more salts to the soil and make things worse.

Choose the right crops and irrigation: If the salt problem won’t go away quickly, work with it. Here are some suggestions:

1. Grow salt-tolerant crops like barley–grain, wheatgrass–tall, triticale–grain, oats–forage, or oats–grain because these crops can still produce under moderate to high salinity conditions. They require less leaching, help maintain soil cover, and give you time to improve soil health without completely sacrificing yield.
2. Use drip irrigation for efficiency, especially where water conservation is critical, but understand how salt behaves with this system. Drip irrigation wets only a narrow zone, leaving the rest of the soil relatively dry. As water is taken up by plants or evaporates, salts are left behind and tend to concentrate at the edges and surface just above the wet spot created by drip irrigation. Over time, this creates a ring of high salt concentration just outside the root zone. These salts can wash back into the root zone, stressing or damaging plants. To avoid this, plan occasional leaching irrigations to flush salts deeper into the soil profile, especially before planting or during cooler months when evapotranspiration is low.
3. Be cautious with furrow irrigation as it can move salts into the seedbed because, as water moves across the furrow, it dissolves surface salts and redistributes them toward the center of the bed where crops are planted. This creates high salt concentrations near seed zones, especially under hot, dry conditions where evaporation is high.
4. If you're using sprinkler irrigation, watch out—salt in the water can settle on your crops’ leaves and burn them, especially in dry, sunny conditions. Those fine droplets might look harmless, but they leave salt behind as they dry, scorching leaf edges and slowing plant growth. If you're thinking of using flood irrigation, know that it can help push salts deep into the soil, and it's great for leaching if your soil drains well and your field is level. But don’t let water sit too long because standing water in low areas can cause waterlogging and allow salts to build back up where your crops need to grow.

Prepare the field before planting: Before you plant, apply enough water to leach salts below the seed zone to give your seedlings a clean start. If your soil drains well, pre-irrigation is one of the best ways to reduce salinity where it matters most. Use raised beds and space your rows wide enough to prevent salts from concentrating where the seeds are placed. Once the crop is in, irrigate more frequently but with smaller amounts. This helps keep salts diluted in the root zone and prevents them from accumulating near the surface where roots are growing.

Mistakes to watch out for

1. Applying gypsum without knowing your soil’s sodium levels
2. Assuming all white crusts mean the same problem
3. Ignoring irrigation water quality
4. Treating saline and sodic soils the same way

In addition to EC, SAR, and ESP, other soil characteristics like texture, type of clay, CEC, organic matter content, calcium carbonate levels, depth to groundwater, and overall soil profile also influence how a field responds to salts and what management steps will be most effective. This information can be found in your local county soil survey, available through the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) offices across Nevada.

References

1. Barker, B., Cardon, G., Yost, M., Stock, M., Creech, E., & Gale, J. (2023). Managing saline and sodic soils and irrigation water. Utah State University Extension. 
2. Bauder, T. A., Jr., Davis, J. G., & Waskom, R. M. (2014). Managing saline soils. Colorado State University Extension. 
3. Davis, J. G., Waskom, R. M., & Bauder, T. A. (2012). Managing sodic soils. Colorado State University Extension. 
4. Parent, V., & Koenig, R. (2010). Solutions to soil problems I. High salinity (soluble salts). Utah State University Extension. 
5. Re, M., Tomasek, A., Hopkins, B., Sullivan, D., & Brewer, L.  (2022). Managing salt-affected soils for crop production. Oregon State University Extension Service. 
6. USDA-NRCS. (2014). Guides for educators. In Soil health–soil pH. USDA-NRCS. 
7. Waskom, R. M., Bauder, T., Davis, J. G., & Andales, A. A. (2012). Diagnosing saline and sodic soil problems. Colorado State University Extension.