How to Measure Water Content in Plants

Water is essential for plant growth and development, and it is important to know how to accurately measure the water content in plants. Measuring water content can help determine whether plants are being over or under-watered, and can also provide valuable information for irrigation management. Here are several methods for measuring water content in plants:

Method 1: Oven-Drying Method

The oven-drying method is a common and reliable technique for measuring water content in plants. Here are the steps:

Collect plant tissues and weigh them to determine their fresh weight.

Place the plant tissues in an oven at a temperature of 70-80℃ for 24-48 hours.

Once the plant tissues have been oven-dried, weigh them to determine their dry weight.

Calculate the water content as the difference between the fresh weight and the dry weight, divided by the fresh weight.

For example, if the fresh weight of the plant tissues is 100 grams and the dry weight is 20 grams, the water content would be calculated as:

(100 – 20) / 100 = 0.8 or 80%

Method 2: Electrical Conductivity Method

The electrical conductivity method measures the electrical conductivity of plant tissues to determine their water content. Here are the steps:

Collect plant tissues and finely chop them into small pieces.

Place the plant tissue samples in a container filled with distilled water and let them soak for several hours.

Measure the electrical conductivity of the water using an electrical conductivity meter.

Calculate the water content using a calibration curve or an equation based on the electrical conductivity.

The electrical conductivity method is a quick and non-destructive method for measuring water content, but it may be less accurate than the oven-drying method.

Method 3: Tensiometer Method

The tensiometer method measures the tension or suction of the soil around plant roots to determine the water content of the plants. Here are the steps:

Insert a tensiometer into the soil near the plant roots.

Monitor the tensiometer daily and record the reading.

Once the reading stabilizes, it indicates that the soil has reached a steady-state equilibrium and the water content of the plants can be determined.

The tensiometer method is commonly used for measuring soil moisture, but can also be used to indirectly measure the water content of plants.

Conclusion

Measuring water content in plants is a crucial process for plant growth and maintenance. The oven-drying method, electrical conductivity method, and tensiometer method are some of the most common techniques used for measuring water content in plants. Each method has its advantages and disadvantages, and the selection of the appropriate method depends on the plant species and the purpose of the measurement.