Vernier Software and Technology
Vernier Software & Technology

Soil pH

Figure from experiment 6 from Earth Science with Vernier


When you think of pH, you probably think of liquid acids and bases. But soil can be acidic or basic, too. Soil pH, sometimes referred to as soil acidity, can be expressed using the pH scale. The pH scale ranges from 0 to 14. Soils with pH above 7 are basic or sweet. Soils with pH below 7 are acidic or sour. A soil with a pH of 7 is neither acidic nor basic, but is neutral.

The pH of soil is an important factor in determining which plants will grow because it controls which nutrients are available for the plants to use. Three primary plant nutrients – nitrogen, phosphorus, and potassium – are required for healthy plant growth. Because plants need them in large quantities, they are called macronutrients. They are the main ingredients of most fertilizers that farmers and gardeners add to their soil. Other nutrients such as iron and manganese are also needed by plants, but only in very small amounts. These nutrients are called micronutrients.

The availability of these nutrients depends not only on the amount but also on the form that is present, on the rate they are released from the soil, and on the pH of the soil. In general, macronutrients are more available in soil with high pH and micronutrients are more available in soil with low pH. Figure 1 shows the effect of pH on the availability of nutrients in the soil.


In this experiment, you will

  • Use a pH Sensor to measure the pH of soil samples.
  • Identify any nutritional problems plants would have in that soil.

Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

Standards Correlations

See all standards correlations for Earth Science with Vernier »

Earth Science with Vernier

See other experiments from the lab book.

1Introduction to Data Collection
2Exploring Magnetism
3Where IS North?
4Searching for Iron Ore
5Sea Floor Spreading
6Soil pH
7Soil Salinity
8Soil and Acid Rain
9Soil Temperature
13Total Dissolved Solids
14Water Treatment
15Salinity of Ocean Water
16Acid Rain and Its Effect on Surface Water
17Freezing of Ocean Water
19Mapping the Ocean Floor
20Are All Sunglasses Created Equal?
21Comparing Sunscreens
22UV Light and Clothing
23Reflection and Absorption of Light
24The Greenhouse Effect
25Land and Sea Breezes
26Relative Humidity
27Dew Point
28Wind Chill
29Seasons and Angle of Insolation
30Fossil Fuels
31Solar Homes
32Photovoltaic Cells
33Wind Power
P1Air Temperature
P2Air Temperature and Relative Humidity
P3Ground Temperature
P4Barometric Pressure
P5Measuring Particulates
P6Weather Stations

Experiment 6 from Earth Science with Vernier Lab Book

<em>Earth Science with Vernier</em> book cover

Included in the Lab Book

Vernier lab books include word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.

Buy the Book

Dev Reference: VST0111

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