How to determine soil moisture

Soil moisture plays a crucial role in gardening, affecting the health and growth of plants. Properly assessing moisture levels helps maintain optimal conditions and prevents issues like overwatering or drought. This article explores how to determine soil moisture using a simple calculation formula and a practical example. Learn how to measure moisture correctly and what steps to take if the soil is too dry or waterlogged.

Calculation formula

Soil moisture (%) = (Mass of water in soil (g) / Total mass of soil (g)) × 100


  • Mass of water in soil: the mass of water contained in a given volume of soil (g).
  • Total mass of soil: the total mass of the given volume of soil (g).

The exact values for saturation and water volume in the soil will vary depending on the soil type. For example, values for black soil will differ from those of sandy or clay soils.

How to use the formula in practice

In the garden, you can roughly estimate soil moisture using the following method:

1. Determine the total mass of the soil:

   a. Weigh a plastic container and record the value.

   b. Fill the container with soil and weigh it again. Subtract the initial weight of the container to get the soil's weight.

2. Dry the soil: spread the soil on a sheet of paper and leave it in the sun or a warm place for several hours until completely dry. Weigh it again to determine the amount of water in the soil.

3. Calculate soil moisture: Use the formula mentioned above to calculate soil moisture.

Example calculation of soil moisture:

For example, if the total mass of moist soil initially was 500 g and after drying it became 400 g, the mass of water in the soil was 100 g. Therefore, the soil moisture would be calculated as follows:

Soil moisture (%) = (100 g / 500 g) × 100 = 20%

  • The moisture content of your soil is 20%.

This method allows you to estimate soil moisture in your garden approximately, but for more accurate results, it is recommended to use specialized instruments for measuring soil moisture.

Characteristics of different soil types

Soil moisture for plants in the garden depends on the soil type and the specific needs of the plants. Here are some general recommendations:

Approximate moisture values for different soil types:

1. Sandy soil: for sandy soil, the optimal moisture content is around 10-20%. This type of soil dries out quickly, so frequent and light watering is usually needed to maintain moderate moisture.

2. Clay soil: clay soil has good water retention capacity, so its optimal moisture is around 20-30%. However, excess moisture can lead to root rot, so it is important to avoid overwatering.

3. Loamy and silt loam soil: these soil types have optimal moisture levels around 20-30%. They provide good drainage and water retention, which promotes healthy plant growth.

4. Black soil has good water retention capacity and usually has an optimal moisture content of around 20-30%. This type of soil provides good nutrition for plants and stable moisture levels.

It is important to remember that these values are approximate and can vary depending on specific conditions and plant requirements. Regular monitoring of soil moisture and responding to changes will help maintain the health and growth of plants in your garden.

Now that you know how to determine soil moisture yourself, you understand that this process requires attention and regular monitoring. Proper soil and plant care in the garden will help maintain optimal conditions for their growth and development.

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