Best Soil Test Kits & Meters Buyers Guide for 2017

Testing your soil is a very important contribution to the health of your plants. Plants require the right pH level (the amount of acidity and alkalinity) in order to best utilize all the nutrients in the soil. Every plant has a different pH preference which is an important fact for all growers to know. Plants also need nitrogen, potash, and phosphorus, in addition to other balanced chemicals. Nitrogen (N) is primarily responsible for the nutrition of plants. It helps to produce green leaves and healthy leaf growth. If your plants are deficient in nitrogen they can have stunted growth and yellow leaves. If plants get too much nitrogen it may cause delayed flowering and overabundant foliage. This, in turn, increases the plant's chances of becoming diseased, and the resulting fruit will be of an inferior quality.

Potash helps to promote protein synthesis by forming carbohydrates which strengthen the plant. A correct amount of potash improves the flavor and color of fruit, benefits early growth, and aids cold hardiness and stem strength. If plants are deficient in potash they usually develop poor root systems and are frequently stunted. The plant leaves tend to be curled, spotted, and have a dried out appearance at the edges. Crop yields for plants with potash deficiency will most probably be low.

All growing plants require phosphorus, which is a major component of seed development and plant genetics. A phosphorus deficiency can cause seed sterility and stunted growth. A sufficient amount of phosphorus in the soil will increase the seed yield, assist plant maturity, augment the development of fruit, aid in the resistance of the plant to winterkill and disease, and also increases the plant's vitamin content.

I've done the hard work...the best soil test kits & meters for 2017:

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Model

Tests

Cost

Our Rating

Luster Leaf Rapitest

pH, Nitrogen, Phosphorus, Potassium levels; 40 Tests in Total

$

5 out of 5

PH Soil Meter

Moisture Meter, pH Acidity and Light Sensor

$

5 out of 5

Soil Ph & Moisture Meter

Soil pH and Moisture Meter

$$

4.5 out of 5

Dr.Meter Soil Moisture Meter

Moisture Meter

$

4.5 out of 5

Hanna Instruments Temp Meter

pH/EC/TDS Temperature Meter

$$$$

4 out of 5

Here are my top choices for the best soil tests kits & meters:

Soil Test Kit Reviews

Pros

  • plus
    Contains 40 total tests, including tests for nitrogen, pH, potassium, and phosphorus
  • plus
    Uses innovative color-coded, specially designed patented comparators and capsule system
  • plus
    Includes an eyedropper for easy transfer of solution and a pH preference list with information on more than 450 plants

Cons

  • minus
    Tube can be difficult to fill properly
  • minus
    Some reviewers found the pH result to be inaccurate and recommended sending soil samples out to be tested

We rated the Luster Leaf 1601 Rapitest Soil Test Kit 5.0 out of 5 stars, and is the editor's choice for an inexpensive, easy to use test kit that provides fast, simple, and accurate results. No experience is necessary to perform the 40 different tests included. This kit provides four separate color comparators for N, pH, potassium, and phosphorus. The simple process involves taking a sample of soil, mixing it with a little water, transferring a portion of solution to the unique color comparator, adding a little powder from the capsule, shaking it, and then watching the color develop. Note the test results, and you're ready to go - all in a few minutes!


Pros

  • plus
    Easy to use soil meter is eco-friendly, and its portable, compact design is convenient for either outdoor or indoor use
  • plus
    Well made accurate inexpensive tester provides quick and accurate results
  • plus
    Eliminates overwatering for both indoor and outdoor plants

Cons

  • minus
    Moisture sensor doesn't work well if the plant name isn't listed on packaging

We rated the pH Soil Meter, 3-in-1 Soil Tester Kit 5.0 out of 5 stars, and is an excellent moisture meter, light, and pH acidity tester. Its responsive probe senses soil changes and displays accurate values to the user. No electricity or batteries are used by this product, making it environmentally friendly. Moisture is measured by inserting the probe completely into the soil to reach the root level. The correct moisture level will be displayed, and the user simply needs to refer to the included chart to find out watering needs.

Light is measured by holding the meter next to a plant and facing a light source (don't touch the sensing element which is located underneath the gauge!). Check light level and refer to the included chart for correct light requirements. To test soil pH, insert the probe into the soil. A pH reading that's less than 7 is acidic, and readings greater than 7 indicate an alkaline soil.


Pros

  • plus
    Longer, more slender 295mm electrode for deeper soil penetration
  • plus
    Self-powered (no battery required), reliable, and accurate
  • plus
    Metal probe/electrode is waterproof and has passed strict safety and quality standards

Cons

  • minus
    Probe is a little too long and soil must be very wet for pH to respond
  • minus
    Meter tends to give random results, necessitating 3-4 measurements for each plant

This quality dual soil pH and moisture meter is rated 4.5 out of 5 stars (by us), and provides simple, accurate checking of soil moisture level and pH balance (alkalinity and acidity). Its extra long probe allows users to measure significantly below a plant's root zone. This meter is perfect for commercial use (orchards, vineyards, lawn maintenance, and field production) and home use (planters, lawn maintenance, and gardens).

This product includes 1 moisture and soil pH meter and 1 instruction manual. It works as advertised, gives accurate pH level readings, and is good for either commercial or home use.


Pros

  • plus
    Plug and read - no electricity or batteries needed
  • plus
    Easy color-coded reading system
  • plus
    Simply push probe down into soil and get immediate results

Cons

  • minus
    A few reviewers noted that the soil meter was inaccurate and occasionally showed the wrong pH and moisture measurements

The Dr. Meter Soil Moisture Sensor Meter And Hygrometer Moisture Sensor For Farm, Garden, And Indoor And Outdoor Plants is rated 4.5 out of 5 stars according to our testing. This product features simple-to-read moisture levels (utilizing 10 scales), a portable, compact design, and is perfect for either indoor or outdoor use. It features an 8-inch stem for full root level penetration. Just plug in the probe and you're ready to measure your soil's moisture content!

Range 1-3, dry to very slightly moist, is good for cacti and other thick-leaved plants; range 4-7, lightly moist to moist, is preferred by most plants (begonias, ficus, geraniums, azaleas, etc.); and range 8-10 is best for orchids.

This 4-in-1 instrument is a light and temperature sensor (measures sunlight intensity and temperature using an 8 in. (200mm) probe), and also tests moisture and pH balance. Readings are clearly displayed on a large LCD screen. This product also features an automatic power-off function and a low battery indicator.


Pros

  • plus
    Quality starter set with water-resistant meter that tests electroconductivity, pH, and total dissolved solids
  • plus
    Meter is simple to adjust and VERY precise
  • plus
    Accurate and easy-to-use tool for all hydroponic gardening

Cons

  • minus
    Expensive compared to other models

We rated the Hanna Instruments Temperature Meter is rated 4 out of 5 stars (due to it's price compared with other models), and is designed especially for use in greenhouses, hydroponics, nurseries, and farms. It comes equipped with a combination probe/connector and 3.3 ft. (1 m) of cable, 9V battery, cleaning and calibration solutions and sachets, and instructions.

This professional product uses ATC (Automatic Temperature Compensation) which eliminates the necessity of performing extra calculations, an alert system which advises the user of potential measurement error or low battery, and on-screen calibration and user guides. This higher-end product is frequently used by manufacturers, researchers, scientists, and hobbyists in winemaking, agriculture, and aquaculture.

WHY SHOULD YOU TEST YOUR SOIL?

All plants require the right nutrients to grow. These nutrients include potash, phosphorus, and nitrogen (K, P, and N), which play a similar role in the growth of plants as protein, carbohydrates, vitamins, and minerals do in human health. We recommend testing your soil regularly all through the growing season, and particularly before you plant in Springtime, and when you're preparing beds in the Fall.

Houseplants are generally happiest with slightly acidic soil (pH 6.5 - 7). Highly alkaline soil will stunt plant growth and cause leaf color to fade. Soil that is too acidic causes leaf droppage and wilt.

HOW TO DETERMINE THE BEST SOIL TEST KIT TO BUY

People that are searching for soil test kits should keep in mind a number of options:

  1. If you are just interested in testing the pH in your soil there are a number of excellent inexpensive choices in the marketplace.

  2. If you want a combination soil tester, moisture meter, temperature gauge, and light sensor, and are interested in knowing non-pH levels of chemicals in your garden, it's wise to compare the various kits that are available on Amazon, eBay, and other review sites online. Keeping in mind your budget, research the different options available, and read the negative as well as the positive reviews.

  3. The soil tester kits rated in this article have been carefully researched and selected from a broad group of hundreds of kits. These kits are highly recommended, and any one of our five options could be the perfect soil tester kit that will fulfill your needs!

WHAT IS A SOIL MOISTURE METER?

A soil moisture meter measures the volume of water present in the soil and is the most effective and scientific way to water your plants. Moisture meters (also called moisture sensors) most commonly use a probe to find out whether your soil is too dry, too wet, or just right. Different moisture meters are used for outside irrigation systems as well as for monitoring indoor plants.

Outdoor soil moisture meters should be located in the driest spot possible, and at least 5 feet away from any structure, downspout, overhang, or tree canopy. Studies by the University of Florida show that soil moisture meters are able to reduce residential outdoor water usage by an average of 50%. Besides reduced water consumption, SMMs (soil moisture meters) can help the soil to minimize plant wilting and retain the optimum moisture saturation. SMMs can also contribute to reduced soil leaching or runoff, a deeper growth of plant roots, and create a less favorable environment for fungal diseases and insects.

Moisture meters are invaluable for measuring the humidity in your soil. A graduated dial or LED display will indicate whether your soil is wet, moist, or dry so that a garden or lawn may be watered correctly. A long probe (8 inches or more) is used to penetrate the soil to the root level. By using an SMM, you will know immediately whether you need to water or if your plants need another day or two to dry out.

Most soil meters show readings on a display from 1 (dry) to 10 (wet). Accompanying guides will list correct moisture requirements for 50 to 450 different types of plants. For instance, if the meter measures a 1, that indicates sufficient water for geraniums but drought conditions for ferns, which have an optimal moisture level of 6. Soil moisture meters are ideal for houseplants, hanging baskets, patio planters, and window boxes. Meter probes should never be left in the soil since that will corrode the probe rapidly.

DO I NEED MORE THAN JUST A pH SOIL TESTER?

Knowing the pH of your soil is an important first step, but there are other things to check for. You'll want to test the conductivity of your soil in two ways - by checking the soil's total dissolved solids (TDS) to measure how much fertilizer is already present in your soil, and measuring electrical conductivity to find out the total amount of nutrients present in your soil. This way you'll know just the right amount of fertilizer that your plants need.

Next, you'll want to measure your soil temperature to see what types of crops or plants you can grow. Use a probe to measure temperature at plant depth. There are many lists available which can tell you which crops are able to germinate and at what temperature. This information should also be available on seed packages.
Depending on what plants you are thinking of growing, you will want to check levels of nitrogen, potash, protein, and phosphorus in your soil. If your soil is nitrogen deficient the leaves of your plants will be pale green or yellow because of a lack of chlorophyll. Plants will also be stunted since nitrogen is essential for plant enlargement and cell division.

Low protein in your soil will result in reduced crop yield and can be devastating when you are growing grain crops, especially wheat. Potash or potassium deficiency happens frequently in light, sandy soil. A deficiency will show up as yellow edges, brown spots, or yellow or brown veins. Adding potassium helps plants to grow faster, use water better, resist pests, fight off disease, and produce more crops. Phosphorus deficiency causes plants to take on an abnormal darkish-green color and also stunts their growth. Testing your soil for phosphorus amounts promotes Winter hardiness, root growth, and can even hasten plant maturity.

In addition, you might want to test for secondary nutrients magnesium, calcium, and sulfur, as well as minor nutrients manganese, iron, zinc, copper, chlorine, molybdenum, and boron, depending on the particular soil in your area. Look for a good soil tester that searches for temperature and for necessary nutrients in addition to pH balance for the best results in your garden.

WHAT IS pH?

A pH (potential hydrogen) scale is used to measure how basic (alkaline) or how acidic a liquid is. pH has numbers ranging from 0 to 14. Number 0 to number 7 are acids (0 is the strongest). Number 7 to number 14 are bases (14 is the strongest). Bases and acids are 2 different kinds of chemicals. Virtually all liquids are bases or acids to some degree - it all depends on how many ions they contain. If the liquid contains many hydrogen ions it is classed as an acid. If there are many hydroxide ions present, it is classed as a base.

A pH scale was created by scientists to measure how basic (alkaline) or how acidic a liquid is. Let's take a look at soil pH. Soil pH affects the availability of plant nutrients by influencing the chemical reactions different nutrients undergo. The vast majority of plants grow best in the pH range between 5.5 - 7.5.

The acids featured on the soil scale are as follows: 

  • leaf
    ​​​​Ultra acidic - less than 3.5
  • leaf
    Extremely acidic - 3.5 - 4.4
  • leaf
    Very strongly acidic - 4.5 - 5.0
  • leaf
    Moderately acidic - 5.6 - 6.0
  • leaf
    Slightly acidic - 6.1 - 6.5
  • leaf
    Neutral - 6.6 - 7.3
  • leaf
    Slightly alkaline - 7.4 - 7.8
  • leaf
    ​​​​Moderately alkaline - 7.9 - 8.4
  • leaf
    Strongly alkaline - 8.5 - 9.0
  • leaf
    Very strongly alkaline - greater than 9.0

Natural soil pH is dependent on the mineral composition of a soil's parent material, which is composed of underlying geological material (a drift or superficial deposit or bedrock) which first formed the soil. This means that soil has mineral materials inside it that have undergone some chemical and physical weathering (receiving rainwater from the atmosphere that has been charged with carbon-dioxide). The soil is also affected by the manner in which that soil was transported (by ice (glacier), water, gravity, or wind).

Soil acquires acid by rainfall, decomposition of organic material, plant growth, the use of fertilizer, acid rain, and oxidation of some minerals, either by mine spoils or by acid sulfate soils. Soil alkalinity happens when there's insufficient water flow through the soil to be able to leach any soluble salts. This occurs because of arid climate conditions or insufficient internal soil drainage.

WHY IS pH LEVEL IMPORTANT FOR MY GARDEN?

All plants need different levels of acidity for proper growth. Soil acidity can affect the dissemination of important soil nutrients, and sometimes an imbalance is able to block a plant's capacity to absorb nutrients. That's why it is very important to test pH levels, especially if you are going to plant a garden for the very first time in soil that hasn't been tested for acidity.

Plants require the right pH level (alkalinity/acidity) to control how fully they can use all the nutrients that are present in the soil (like iron and nitrogen). Most plant nutrients can be easily dissolved if your soil has a pH level between 6.0 and 7.5. If the pH is below 6.0, your plants might not be able to access such nutrients as potassium, phosphorus, and nitrogen. If your soil's pH level is greater than 7.5 they might not be able to access manganese, iron, or phosphorus.

If you live in a drought-prone area you may have alkaline soil. If you live in an area with forest cover and heavy rainfall you might have moderately acidic soil, and your soil might be neutral if you live in a region of prairie cover and light rainfall.

Once you know the pH level of your particular soil you'll be able to select plants having similar pH preferences, and you can stay away from those plants that won't thrive in your particular type of soil. You'll also have the necessary knowledge to be able to supply your plant's special growing needs. You will know both when to fertilize and also how to adjust the pH more effectively, accurately, and economically.

If your soil's too acidic, you can add alkaline material or lime. Use calcitic limestone, which contains calcium carbonate, for most applications. Use dolomitic lime if your soil testing shows that there's a magnesium deficiency in your soil. You can also raise your soil pH if you apply wood ashes, which are 70% calcium carbonate, and also contain phosphorus, trace minerals, and potassium. Be careful not to overapply it, though, because you might end up with a serious soil imbalance. Remember to read all directions carefully.

If your soil's too alkaline, you'll need to add some acidity. The most commonly used material for this is powdered elemental sulfur. One pound of sulfur every 100 square feet can lower your soil's pH 1 point. Mixing shredded leaves and peat moss with your soil can also lower its pH level. Once again, use care in applying these materials. Test your soil first and then thoughtfully apply the necessary materials.

CONCLUSION

Purchasing a soil tester kit can be one of the nicest things you can do for your garden, your plants, and for yourself. The kits that have been reviewed here are reasonably priced, contain a wide assortment of measurements and options, and can accomplish in minutes what may have taken weeks and months in the past when soil testing could only be obtained through sending away samples in the mail or by visiting a local agricultural station. The convenience of these home soil tester kits cannot be overstated. Good luck with your soil testing!

About the author

Mark Kelly

Hi, I'm Mark the owner of Yard Care Gurus. I love to be outside working on my lawn, planning my next project. I created this website to help people like you find the best products for yard care and great advice. Thanks for stopping by!