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Measuring Soil pH
Nutrients Soil hydroponics

Posted By: Plant Magic

Understanding How Soil pH Affects Plant Nutrients

Soils require more than hydroponic nutrients to ensure plants grow as healthy as they should. Plant Magic soil solutions help your crops develop strong and healthy, with high yields. Your soil’s pH level is something you need to keep in mind when growing crops, as certain plants can’t withstand either extreme.

The ideal soil pH levels vary from crop to crop, however, levels of between 6.0 and 7.5 are typically acceptable for most plants, with 6.5 being the more desirable level. In hydroponic growing, pH levels between 5.8 and 6.2 are usually ideal. The majority of nutrients become available at around this pH range and provide plants with the nutrient balance they require.

But how does pH affect plant growth?

Magne-Cal +


Strongly Acidic Soils

Factors such as rain and microbial activity can affect soil pH levels, with rain being slightly acidic (pH 6.5) and carrying very small amounts of carbonic, nitric, and sulfuric acid amounts. Should more than 25 inches of rainfall per year in any area, calcium and magnesium are two nutrients that are easily leached from the topsoil, which creates acidic conditions.

Similarly to how plants take needed nutrients from the soil to ensure plant growth, microorganisms in the soil also require organic matter, nutrients, and plant residue to guarantee appropriate activity. The growth of these microorganisms releases into the soil carbon dioxide, which doesn’t escape the soil easily and reacts with moisture to create carbonic acid.

A pH level of 5.5 translates to reduced microbial activity, with pH levels below 4.6 often too acidic for plants. Strongly acidic soils will represent major nutrient deficiencies of:

  • Nitrogen
  • Potassium
  • Sulphur
  • Phosphorus
  • Magnesium
  • Calcium

The increased solubility of iron and aluminium restricts calcium absorption, the latter which is at already extremely low levels in acidic soils. Phosphorus reacts with iron and aluminium in acidic soils, forming compounds that are less soluble.

Adding calcium carbonate to the soil or introducing it with a specialised booster such as Magne-Cal + will help to increase the soil’s pH level and the calcium’s availability in the soil.


Strongly Alkaline Soils

A pH level above 7.5 translates to a lack of iron available to plants, while pH levels above 8.3 are often too alkaline for most plants to survive in. Strongly alkaline soils will see trace element deficiencies such as:

  • Iron
  • Copper
  • Zinc
  • Boron
  • Manganese
  • Nitrogen

Strongly alkaline soils will have too much calcium available to plants, which is problematic due to this nutrient regularly combining with phosphorus and boron. These soils will have a boron deficiency, however, phosphorus levels are high and can cause stunted growth and leaf discolouration.

Phosphorus reacts with magnesium and calcium in acidic soils, forming compounds that are less soluble. Micronutrients have a tendency of becoming less available with soil pH levels above 7.5. Molybdenum is an exception, as it becomes more available in acidic soils and in soils with moderate alkaline levels.

Utilising a complex PK booster, such as the Platinum - Premium PK 9-18 will help to balance your soil’s pH levels and prevent them from being too alkaline.

Platinum - Premium PK 9-18

Our expert team here at Plant Magic is always available to answer any question you might have about alkaline or acidic soils or other specific factors that affect plant growth. Contact us on 01695 554 080 to know more about our products and how we can help to transform your crops into happy and healthy plants.

Our Blog: Hydroponic Tips & Tricks

Whether you are an expert who already has a thriving crop of healthy plants, or you are trying to grow your very first hydroponic yield, we can help you to grow the strong and healthy crops you have always wanted.

Here at Plant Magic Plus, our team of gardening experts work very hard behind the scenes to provide you with the high quality nutrients, additives and growing media that will help you to get the most out of your growing plants.

But we understand that successful horticulture is about more than just having good quality chemicals, nutrients or fetilisers, that's why we have written this blog to provide you with the insights, tips and techniques you will need to give your garden that extra magic touch.

From helpful advice about watering your plants in soil and a guide to magnesium nutrients, to top tips about growing hydroponic vegetables and a comprehensive overview of microbes, we’ve got everything covered.


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