Why Should I Try Soil Sampling?

Have you ever tried to plant something that just didn’t want to grow, no matter how hard you tried? As you’ve begged, pleaded, and cajoled your lawn to turn greener or your plants to grow taller, perhaps you should have been turning to your soil instead.

We’re big fans of soil testing to fix those growing pains, and you’re about to be, too. Let’s learn more about soil sampling, its importance, and what you’ll learn from a routine soil test so you’ll be able to maintain that green lawn or grow the biggest flowers on the block.

What is Soil Sampling?

Soil testing—or soil sampling, as it’s often called—is a soil-management tool that helps you understand your dirt’s health. A soil test removes elements from the ground (primarily calcium, copper, magnesium, manganese, phosphorous, potassium, sodium, sulfur, and zinc) and measures the nutrients to determine how much a plant would grow and thrive, given the state of the elements.

What Can Soil Tests Identify?

Soil sampling provides critical information for the long-term survival of your lawn and plants. Your soil’s nutrition is important, and a soil test gives you the insight to identify several issues, including:

Current nutrient concentrations and deficiencies, including macronutrients and micronutrients—Soil tests can identify nutrient deficiencies and levels of primary macronutrients like nitrogen, phosphorus, and potassium, as well as secondary macronutrients like calcium, magnesium, and sulfur. Soil samples can also identify micronutrients like boron, chlorine, copper, iron, manganese, molybdenum, nickel, and zinc. Understanding how these nutrients are contributing to your soil makeup will give you a starting point for diagnosing larger issues.

Soil pH—On a scale of 0 to 14, soil pH measures how acidic or alkaline (basic) the soil is, with 7 being neutral. Most plants grow best in slightly acidic soil, with a pH between 6 and 6.5, but others prefer more acidic soil. Soil pH that's too high or too low can prohibit a plant from absorbing nutrients.

Organic matter—Organic matter (OM) is made up of living organisms, dead residue, and decomposed material in the soil. Soils with high OM levels retain more moisture, have a crumbly structure, and slowly release nutrients over time, giving your soil a healthy atmosphere to host thriving plants.

Cation exchange capacity—The cation exchange capacity (C.E.C.) measures the total negative charges in the soil that will attract positively charged ions or cations (like calcium, magnesium, and potassium). A soil’s C.E.C. indicates how well it can hold onto plant nutrients, which is crucial for understanding how well the soil will grow plants.

Salinity—While not all soil tests measure salinity, some do measure how much saline is available in the soil. Too much sodium dehydrates the soil and stresses plant roots thanks to a high soil pH.

5 Reasons You Should Be Testing Your Soil

1. Soil Sampling for Soil Health

Soil sampling gives you a good understanding of your soil’s health. It measures a range of chemical, biological, and physical characteristics, including the amount of microbial activity occurring within your soil—giving you a good idea of its quality since the microorganisms help to mineralize nutrients for growth and development. Soil testing also gives you an idea of when your dirt might need an intervention, either with soil aeration or drainage amendments.

2. Soil Testing for Soil Fertilization

Soil sampling helps a gardener make better fertilization decisions. When you know what’s in the soil—or just as importantly, what’s not—you’ll know exactly how much fertilizer and at which nitrogen-phosphorous-potassium ratios you’ll need. You’ll also know if you need to apply mineral and soil amendments, like dolomite lime. Best yet, soil testing helps you to avoid over-fertilizing. This wealth of knowledge enables you to create a healthier lawn and grow more vegetables in your garden.

3. Soil Sampling for Plant Well-Being

Soil testing gives you a good idea about why your plants might be having problems and gives you the tools to improve your soil’s nutritional balance. While your plants need sunlight and water, they also need healthy soil to thrive. Your dirt can also dictate which plants are right for the soil type you’re working with.

The secret to your plant’s success is its soil pH levels. By sampling your soil, you can determine whether yours is acidic, neutral, or alkaline. This helps you determine your soil’s health, but it also helps you choose the right plants to complement your soil type.

4. Soil Testing to Protect the Environment

Conduct soil tests to protect the environment from runoff contamination and dissolve excess fertilizer into the soil. You can also use soil sampling to learn where you shouldn’t apply fertilizer or manure. 

5. Soil Sampling to Save Money

Soil sampling is a great way to save money. When you properly manage your soil’s nutrients, you don’t waste money by overapplying lawn and garden products—especially expensive fertilizers or amendments you don’t truly need. Think of it like this—when you know what’s wrong, you can spend the money on the right fixes.

What Am I Looking for Before and During a Soil Test?

As you’re conducting a soil sample (or even before you need to do so), your soil will give you some telltale signs about its health and well-being. Here are some things to look for: 

Soil structure and workability: How well does the soil break apart in your fingers? Ideal soil has a crumbly quality to it that holds up to slight pressure but isn’t too hard to break apart. Open, porous soils allow water and oxygen to flow freely.

Compaction: Plunge a wire flag vertically in several locations and determine where it starts to bend, which indicates how compacted the soil is. Ideally, you can go down at least a foot before the soil compacts, allowing for roots to grow and fauna to circulate.

Organisms and earthworms: Dig down about six inches and keep an eye out for the great creepy crawlies of the underground—like centipedes, ground beetles, and spiders. Likewise, keep an eye on the surface for earthworm castings and burrows, then see if you can follow them below ground. While you may consider this step gross, it’s indicative of a healthy soil food web.

Plant residue: About a month after you plant, gently dig down around the plant to look for plant residue. Decomposed organic matter is a sign of healthy soil.

Plant vigor: How healthy do your plants look during the growing season? It seems simple, but when they look strong and healthy, odds are that the soil is strong and healthy, too.

Root development: Choose a plant you don’t need to keep (preferably a weed) and gently dig down to the root system. Are the roots white with fine strands, or are they brown and mushy? Brown, mushy roots can indicate serious drainage issues or disease.

Water availability: After a soaking rain, notice how long it takes your plants to look dehydrated again. If it seems like that happens quickly, your soil is likely the culprit—it may be compacted, and the water can’t get to the roots.

When Do I Sample the Soil?

Just like anything related to your lawn or garden, timing is everything. That’s certainly the case to know when to conduct your soil test. 

You should conduct a soil test every three to five years (usually two to three years for sandy soil and three to five years for clay soil) once your soil is established, typically in the fall or just after the first thaw in spring. (If you’re new to your land or are dealing with massive issues during the growing season, you can test your soil more frequently.) Fall is a recommended time to sample your soil for the following reasons: 

• The soil temperatures are above 50 degrees Fahrenheit
• The growing season is over (or nearly over)
• The nutrients from the fertilizers or mineral amendments you’ve applied have time to soak into the soil before the next planting season starts

How to Conduct a Soil Test 

A properly conducted soil test contains a general sample that has been collected from various spots around the area you’re testing. To sample the soil:

Step 1. Use the proper garden tools. You’ll need a clean shovel and soil sampling probe. Please note that rusty tools will impact the results of your soil sample.

Step 2. Collect a probe or core of soil from 10 to 15 different locations (at least four inches deep for lawns or six to eight inches deep for gardens). Be consistent with your collections—dig a representative sample from across your entire lawn, dig the size and depth of the hole from each sample, and dig during the same weather conditions throughout the sampling period for best results.

Step 3. Mix the same soil samples in a bucket (lawn with lawn, garden with garden).  

Step 4. Label the soil sample mixture.

What Types of Soil Sampling Can I Choose From?

Your own soil sampling needs will depend on many factors. Rocky Mountain BioAg® partners with International Ag Labs to offer four different types of soil sampling: 

Rocky Mountain BioAg® Basic Soil Test 

Our Basic Soil Test, the entry-level soil sampling kit in our lineup, is anything but basic! It offers detailed insights about the soil’s nutrient profile and overall health by analyzing it and testing for boron, which allows you to make informed decisions for a plant’s optimal growth and sustainability. 

Rocky Mountain BioAg® Basic Plus Soil Test

While our Basic Plus Soil Test also offers a thorough analysis of your soil’s overall health, this version of the test goes a step above. In addition to the detailed soil analysis and boron testing, this kit also provides a Formazan—Microbial Activity & Soil Index reading to get a better idea of your soil’s microbial activity. 

Rocky Mountain BioAg® Standard Soil Test 

Our Standard Soil Test gives you a comprehensive look into your soil’s nutrient health, with an emphasis on the sulfur and organic matter present within your lawn or garden. This soil sample kit focuses on sulfur because sulfates are important components of organic matter and stimulate microbial activity. Sulfur is the primary nutrient used to react against high pH nutrients in the soil, which releases energy that plants use to grow.

Rocky Mountain BioAg® Complete Soil Test 

Last but not least, our Complete Soil Test is our way of throwing the whole kitchen sink’s worth of soil sampling to you in one deluxe kit. This test provides you with an extensive analysis of macronutrients and micronutrients, in part because it includes the option to test for the Cation Exchange Capacity (C.E.C) within the soil’s organic matter, which varies by soil pH.

What’s the “At-Home” Version of a Soil Sampling Kit? 

The great news is you don’t need an expert to conduct any of the professional soil sampling kits we offer. We send everything you need right to your door with instructions about how to get it back to our labs for analysis.

But sometimes, you need a faster operation. For quick and dirty results (pun definitely intended), use our microBIOMETER. It’s the only rapid soil testing kit on the market, and it allows you to capture and analyze the scientific data you need to monitor and evaluate your soil’s health. By testing for soil microbes at home to correlate microbial biomass with soil fertility levels, farmers and gardeners can make immediate predictions for crop outcomes and revolutionize how they manage their growing success. 

How Do I Interpret the Results of a Soil Sample? 

All four of our lab soil sample kits come with everything you need to collect a thorough sample and ship it to your desired International Ag Labs location. We then send you an email with the results so you know which products to choose, even smack dab in the middle of a busy growing season.

However, we do not include test interpretations with the results from any of our mail-in soil testing kits. To better understand your soil sampling results and receive recommendations for how to best improve your soil, we can assist you by conducting a soil test interpretation. This interpretation will let you know what amendments, fertilizers, and nutrients are needed to meet—and hopefully exceed—your growing goals.

Any healthy, thriving growing space starts with healthy soil. Soil sampling gives you the knowledge you need to succeed, so you’ve got the lawn, vegetable patch, or flower garden that everyone on the block envies!