PH Soil Meters
pH Soil Meter Technical
What is soil pH?
Soil can exhibit either alkaline or acidic properties (sometimes called basicity). The pH of soil serves as a measure of its acidic or alkaline levels. Typically displayed on a colour chart, red indicates acidity and blue represents alkaline.
The pH value indicates the concentration of hydrogen ions within the soil. The pH scale is logarithmic, meaning lower pH values signify higher hydrogen ion concentrations, showing strong acidity. Garden soil generally falls within a pH range of 3.5 to 10.
The three primary classifications for soil pH are as follows:
- - pH 0 to 6.5: Acidic
- - Neutral.
- - pH 7.5 to 14: Alkaline
The content of the soil determines the soil pH. Other factors that can affect the acidity of soils include:
- - Weather processes
- - Root respiration
- - Plant growth
- - Fertiliser
- - Acid rain
- - Addition of minerals to the soil
- - Water flow
Why is soil acidity important?
Gardeners must be attentive to their soil's acidity. The pH level significantly impacts plants' solubility and absorption of nutrients and chemicals. The ability of plants to absorb nutrients depends on the soil acidity.
The ideal range for plant growth is around a neutral pH level, which falls between 5.5 and 7.5. Most of the seventeen essential nutrients required for plants are readily available in the soil within this range.
Moreover, the pH level also influences the activity of microorganisms responsible for decomposing organic matter in the soil. Strong acidity can hinder the bacteria responsible for decomposition, reducing available nutrients in the soil.
Consequently, inadequate blooms or crops may result from imbalanced soil pH levels. As previously mentioned, soil acidity can even affect the colour of certain plants. For instance, acidic or alkaline soil affects the growth of colours of hydrangea flowers.
The following table illustrates the availability of minerals to plants based on the soil's acidity. Green indicates a strong mineral balance, while amber indicates a less robust balance.
How does soil acidity affect plants?
Acidic soil
Ericaceous and calcifuge plants thrive in acidic soil conditions. These plants have adapted to flourish in such environments and must be better suited to alkaline soils.
If grown in alkaline-heavy soil, these plants may display yellow leaves, a condition known as lime-induced chlorosis.
This occurs because alkaline soil lacks essential nutrients like iron, which are crucial for their growth. As a result, plants suffering from this condition will struggle to develop and may eventually perish.
Examples of ericaceous and calcifuge plants that are ideal for planting in acidic soil include:
- - Rhododendrans
- - Azaleas
- - Heathers
- - Blueberry
- - Camellia
- - Lily
- - Pieris
- - Magnolia
Alkaline soil
Calcicole plants are well-adapted to thrive in alkaline or lime-rich soil. Calcicole plants grown in acidic soil exhibit comparable effects, such as chlorosis, stunted growth, and curling leaves. These effects stem from the availability of nutrients in the soil.
Alkaline soil contains elevated levels of calcium when compared to acidic soil. Due to the presence of chalk and limestone in Britain, many commonly find soil rich in calcium, resulting in chalky soils.
Examples of calcicole plants that are ideal for planting in alkaline soil include:
- - Ash trees
- - Honeysuckle
- - Lilacs
- - Clematis
- - Syringa
- - Phacelia
- - Polemoniums
- - Lavender
How does the soil pH meter work?
The EL-SM-METER3IN1 is an electronic soil pH tester instrument which requires no batteries or external power. So, let’s explain that apparent contradiction first. Both batteries and solar power provide electricity.
This Monitor incorporates a light sensor to give a measurement of sunlight. This sensor works by generating a voltage that depends on the strength of the light. Although it is small for a solar cell, there is enough power to operate the Monitor.
But other power sources are available. Every time the probes are inserted into moist soil, this monitor makes a battery. The probes are made of different metals (there are four separate contacts on its two probes, using three types of metal).
When placed in an electrically conducting environment like moist soil, all the components of an electric cell (battery) are in place. The Monitor will still work even in the dark.
The light meter displays the voltage generated by the light sensor. The pH meter displays the voltage generated by its probe/soil battery. The measure moisture meter displays the current passing through the soil, which depends on its soil moisture level.
The indicating meter is a spring-loaded, electric motor that rotates the indicating needle if more electrical voltage is generated.
A clearly labelled 3-position switch gives the choice to select the meter function. Insert the probes into the soil and turn the meter on. The device accurately measures the soil acidity level and provides a much more accurate reading than other testers on the market.
The pH function measures the pH. A lower value below seven increases acidity, whereas a higher number above seven increases alkaline levels. A pH measurement of 7 is a perfect balance being neither acidic nor alkaline. Note that different plants prefer different pH, and not necessarily 7.
Avoid leaving the meter and probes in the soil. Ensure the probes are cleaned after each use for more accurate results and reduce damage to the probes.
Changing your soil pH
There are several ways you can alter the pH of your soil, including:
- - Nitrate-based Fertilisers for acidic soil to raise the pH level.
- - Mineral fertiliser and sulphur to lower the pH level.
- - Lime for acidic soil to raise the pH level.
- - Wood ash for acidic soil to raise the pH level.
- - Aluminium for alkaline soil to lower the pH level.
Vegetables Ideal pH Reading Ideal pH Reading
Bean 6.0 - 7.5 Lettuce 6.0 - 7.0
Broccoli 6.0 - 7.5 Onion 6.0 - 7.0
Brussels 6.0 - 7.5 Pea 6.0 - 7.5
Cabbage 6.0 - 7.5 Pepper 5.5 - 7.0
Carrot 5.5 - 7.0 Potato 4.5 - 6.0
Cauliflower 5.5 - 7.5 Radish 6.0 - 7.0
Cress 6.0 - 7.0 Spinach 6.0 - 7.5
Cucumber 5.5 - 7.5 Swede 5.5 - 7.0
Leek 6.0 - 8.0 Tomato 5.5 - 7.5
Fruit Ideal pH Reading Ideal pH Reading
Blackberry 5.0 - 6.0 Melon 5.5 - 6.5
Cherry 6.0 - 7.5 Peach 6.0 - 7.5
Currant Black 6.0 - 8.0 Raspberry 5.0 - 6.5
Currant Red 5.5 - 7.0 Rhubarb 5.5 - 7.0
Gooseberry 5.0 - 6.5 Strawberry 5.0 - 7.5
Grapevine 6.0 - 7.0 Lawns 6.0 - 7.5
Flowers/Shrubs Ideal pH Reading Ideal pH Reading
Alyssum 6.0 - 7.5 Gladiolus 6.0 - 7.0
Azalea 4.5 - 6.0 Hydrangea Blue 4.0 - 5.0
Carnation 6.0 - 7.5 Hydrangea Pink 6.0 - 7.0
Chrysanthemum 6.0 - 7.0 Hydrangea White 6.5 - 8.0
Clematis 5.5 - 7.0 Marigold 5.5 - 7.0
Daffodil 6.0 - 6.5 Rhododendron 4.5 - 6.0
Dahlia 6.0 - 7.5 Rose 6.0 - 7.0
Fuchsia 5.5 - 6.5
PLANT WATERING GUIDE
Red Zone Green Zone Green Zone Green Zone Green Zone
Plants 1-3 Plants 4 - 5 Plants 5 - 6 Plants 6-7 Plants 6-7
Aloe Parachute Plant Action Plant Amazon Lily Moon Flower
Anchor Plant Pen Wiper African Violet Angel Wings Mosaic Plant
Asparagus Fern Pink Buttons Angle Tears Apostle Plant Mother-In-Law Plant
Baby Jane Pocket Book Plant Aralia False Azalea Mouse Plant
Baby pine of China Poinsettia Bachelor Button Brazilian Firecracker Nut Orchid
Baby’s Breath Queens Tears Boxwood Bridal Wreath Oleander
Beaver Tail Roman Candle Burn Plant Burro's Tail Peacock Plant
Bishops Cap Sand Dollar Cape/Crape Myrtle Butterfly Gardenia Peperomia
Bloodleaf Sedum Chile Bells Caladium Periwinkle
Cactus Shrimp Plant Cloth of God Calla Lily Petticoat Palm
Chicken Gizzard Tiger Jaws Corn Plant Camellia Pitcher Plant
Christ Plant Umbrella Tree Crimson Flag Chenille Plant Polynesian Ti Plant
Crassula Wall Fern Devils Ivy Cobra Plant Pothos
Crown of Thorns White Jewel Dieffenbachia Coleus Prayer Plant
Dumb Cane Green Zone Euonymus Columnea Quaker Ladies
Easter Orchid Plants 4-5 Finger of God Copper Leaf Sansevieria
Euphorbia Airplane Plant Firethorn Croton Saxifraga
Fig, Fiddle Leaf Begonia Flamingo plant Darlingtonia Scindapsus
Firecracker Plant Bird of Paradise Fleur D’Amour Dawn Flower Sea Grape
Flaming Sword Blushing Bride Flower of Heaven Dracaena Palm Spider Plant
Floral Firecracker Bonsai Tree Glory Lily Easter Lily Temple Bells
Foolproof Plant Bromeliad Gold Dust Plant Echeveria Turk’s Cap
Gas Plant Candle Plant Hoya Egyptian Star Cluster Velvet Plant
Geranium Century Plant Impatiens Explosion Plant Verbena
Ghost Plant Ceropegia Kashmir Bouquet False Holly Violet Flame
Glory of Texas Chain Cactus Kiss-Me-Today Fan Iris Wandering Jew
Golden Dew Drop Daphne Lady of the Night Fan Ivy Wax Plant
Good Luck Plant Earth Star Lantern Plant Farewell to Spring Zebra Plant
Hibiscus Echeveria Medicine Plant Ferns
Honey-Bunny Hairy Toad Plant Naked Lady Lily Fiery Love Flower Blue Zone
Ice Plant Hearts on a String Pussy Foot Fig, Creeping Plants 8-10
Ivy Hen and Chicken Queens Jewels Finger Aralia Watering is not
Jade Plant Inch Plant Rouge Plant Fingernail Plant necessary
Jasmine Star Little Stars Rubber Plant Fire Dragon
Jelly Beans Mock Orange Shooting Star Five Fingers
Lantana Norfolk Island Blue Solomon's seal Fuchsia
Little Candles Patience Plant Star of Bethlehem Gardenia
Little Owl Eyes Pearl Plant Victoria Aralia Honey Bells
Living Vase Philodendron Water Melon Jasmine
Lobster Plant Ponytail Jungle Flame
Marguerite Blue Radiator Plant Kalanchoe
Mimicry Plant Sea Urchin Ladies Tresses
Moonstones Stoneface Leopard Plant
Mother of Pearl String of Pearls Magic Flower
Musk Plant Vitamin C Plant Man in a Boat
Panda Plant Youth and Old Age Match me if you Can