lysimetre

A lysimetre, also known as a lysimeter, is a scientific instrument used to measure the amount of water that moves through the soil, typically to study evapotranspiration, which is the sum of evaporation and plant transpiration from the Earth's land surface to the atmosphere. Lysimeters are essential tools in hydrology, agronomy, and environmental science, helping researchers understand water balance and soil moisture dynamics.

Lysimeters consist of a container, often cylindrical, that is filled with soil and vegetation. The container is typically inserted into the ground, with the top surface flush with the surrounding terrain to ensure natural conditions. The base of the lysimeter is designed to collect and measure the water that drains through the soil, known as leachate. Some lysimeters are also equipped with sensors to monitor soil moisture, temperature, and other relevant parameters.

There are several types of lysimeters, including weighing lysimeters, which measure the weight of the soil and vegetation to determine water loss due to evapotranspiration, and drainage lysimeters, which focus on collecting and measuring the leachate. Lysimeters can be used in both field and laboratory settings, providing valuable data for water resource management, crop irrigation, and environmental monitoring.

The use of lysimeters dates back to the mid-19th century, with significant contributions from scientists like Heinrich von Bose and Wilhelm Pfeffer. Modern lysimeters incorporate advanced technologies, such as automated data logging and remote sensing, to enhance accuracy and efficiency. Despite their simplicity in design, lysimeters remain a crucial tool in understanding the complex interactions between soil, water, and plants.