Saline and Alkaline Soils in Arid Regions: How to Improve Difficult Ground

Many growers in hot, dry regions discover that their soil is not just dry and hard – it’s also salty or alkaline. Plants struggle, leaves burn at the edges, and some crops simply refuse to thrive, even with regular watering and fertiliser.

In arid and semi-arid climates like Malta and similar Mediterranean areas, salinity and high pH are common challenges. The combination of low rainfall, intense sun and limited irrigation water can gradually load the soil with salts and push pH upwards.

This guide explains what salty and alkaline soils are, how to recognise them, and practical strategies to improve them, including when it makes sense to bypass native soil and use living soil mixes in raised beds.

What Are Saline and Alkaline Soils?

Saline soil  

• Contains excess soluble salts (often from irrigation water, fertilisers or natural deposits).

• These salts make it harder for plants to take up water, even when the soil looks moist.

• Symptoms often resemble drought stress.

Alkaline soil  

• Has a high pH (typically above 7.5–8.5).

• Certain nutrients (like iron, manganese, phosphorus) become less available to plants.

• Common in areas with calcareous parent material and low rainfall.

In many arid and semi-arid regions, soils can be both saline and alkaline, creating a double challenge for plant growth.

Common Signs Your Soil Might Be Salty or Alkaline

You may be dealing with salinity or high pH if you notice:

• White or crusty deposits on the soil surface

• Plants that wilt or burn at the leaf edges despite regular watering

• Poor germination or patchy growth in certain areas

• Yellowing leaves (chlorosis), especially between the veins, in sensitive crops

• Better performance in pots or raised beds than in the ground, using the same water

These symptoms aren’t proof on their own, but they’re strong clues, especially in hot, dry climates with limited rainfall to wash salts away.

Why Salinity and Alkalinity Are Common in Arid & Semi-Arid Climates

Several factors make salty and alkaline soils more likely in hot, dry regions:

• Low rainfallThere isn’t enough natural leaching to wash salts deeper into the profile or out of the root zone.

• Irrigation water qualityWater from some sources (wells, boreholes, certain municipal supplies) can carry dissolved salts and bicarbonates.

• EvaporationAs water evaporates from the soil surface, salts are left behind and can accumulate over time.

• Calcareous parent materialMany Mediterranean and semi-arid soils form on limestone or other alkaline rocks, pushing pH upwards.

Understanding these drivers helps set realistic expectations: you’re working with a climate and geology that naturally push soils towards salinity and alkalinity. The goal is to manage and mitigate, not magically turn them into deep, neutral loams overnight.

Step 1: Get a Basic Soil Test (If Possible)

Whenever you can, a simple soil test is worth the effort:

• EC (electrical conductivity) gives an indication of salinity.

• pH tells you how alkaline (or acidic) your soil is.

Even a basic lab test or a reliable DIY kit can help you:

• Confirm whether salinity is a real issue or not

• Avoid over-correcting based on guesswork

• Choose crops and strategies that fit your actual soil conditions

TerraSoil-style blends are tested for pH and EC before and after mixing, which is one reason they’re a reliable base when native soil is problematic.

Step 2: Improve Organic Matter and Soil Structure

Whatever your test results, one strategy almost always helps in saline and alkaline soils: adding organic matter and improving structure.

Organic matter can:

• Increase water-holding capacity, reducing the concentration of salts in the soil solution

• Improve structure, allowing better infiltration and deeper rooting

• Support soil biology, which can help buffer some of the effects of high pH over time

Practical options:

• Regular additions of well-made compost  

• Using living soil mixes in key planting areas or as a top layer

• Incorporating mulches that break down gradually (straw, compost, leaf mould)

In very difficult soils, it can be more efficient to build raised beds filled with a TerraSoil-style living mix on top of the native soil, rather than trying to transform the entire profile.

Step 3: Manage Water to Reduce Salt Stress

Water management is crucial in saline soils:

• Avoid very shallow, frequent wateringThis keeps salts concentrated near the surface where roots are.

• Water more deeply when you irrigateDeep watering encourages roots to explore lower, sometimes less saline layers and can help move salts slightly deeper over time.

• If water supply allows, occasional leachingIn some systems, applying extra water to flush salts below the root zone can help – but only where drainage is adequate and water is not extremely scarce.

In containers and raised beds using living soil, salinity is easier to manage because:

• You control the soil mix from the start

• You can avoid high-salt fertilisers

• Deep, well-timed watering and good drainage help prevent salt build-up

Step 4: Use Amendments Carefully (e.g. Gypsum)

In some saline or sodic soils, gypsum (calcium sulfate) is used to help displace sodium and improve structure. However:

• Gypsum is most effective in sodic soils (high sodium) with poor structure, not in all saline soils.

• It doesn’t “fix” salinity on its own, you still need water movement to leach displaced salts.

Before applying gypsum or other amendments:

• Check your soil test for sodium and overall salinity.

• Avoid throwing amendments at the problem without understanding the underlying chemistry.

For many small-scale growers and gardeners, focusing on organic matter, good water management and raised beds is more practical than trying to engineer the entire soil chemistry.

Step 5: Choose Crops and Rootstocks Wisely

Some plants are naturally more tolerant of salinity and high pH than others. In challenging soils, it can help to:

• Choose salt-tolerant or alkaline-tolerant species and varieties where possible.

• Use appropriate rootstocks for fruit trees in alkaline soils.

• Place more sensitive crops in containers or raised beds filled with living soil mixes.

This doesn’t mean you can’t grow anything in saline or alkaline soils, but you’ll get better results by matching crops to conditions and reserving your best, most controlled soil (e.g. TerraSoil beds/containers) for the most sensitive or high-value plants.

When to Stop Fighting Native Soil and Build Up

In some sites, especially in arid and semi-arid regions, native soil is:

• Very shallow and stony

• Strongly saline or alkaline

• Difficult or expensive to amend at scale

In these cases, it can be more effective to:

• Build raised beds filled with a living soil mix

• Use large containers with a high-quality potting mix

• Gradually improve native soil in paths or future beds with cover crops and organic matter, without relying on it for immediate production

TerraSoil’s living soil blends, tested for pH, EC and C:N ratios, offer a controlled environment for roots in these situations, while you slowly work on the underlying soil where it makes sense.

Bringing It All Together

Salty and alkaline soils are a reality in many arid and semi-arid regions. You can’t change the climate or the geology, but you can:

• Understand what you’re dealing with through basic testing and observation

• Improve organic matter and structure to buffer salinity and support roots

• Manage water wisely to reduce salt stress and avoid concentrating salts at the surface

• Use amendments carefully, based on actual soil conditions

• Choose crops and systems (raised beds, containers, living soil mixes) that work with your site, not against it

By combining these strategies, you can turn difficult ground into a more productive, resilient growing system, and where native soil is too challenging, you can create islands of high-quality TerraSoil-style living soil that let your plants thrive despite the conditions.