Leaching / lysimeter

Lysimeters are cylindrical containers filled with natural soil. The water percolating into the soil can be collected at the bottom of these containers. Agroscope’s lysimeters are used to study the water- and mass balance of agricultural soils. In this video, you’ll discover the largest and most modern lysimeter installation in Europe, which has been at Agroscope since 2009.

When a soil is water-saturated and more precipitation falls than is absorbed by plants and than evaporates from the soil, the seepage water percolates to greater depths and reaches the outlet at the bottom of the lysimeter. Here, the seepage volume is measured with a tipping bucket. The seepage water contains readily soluble substances leached from the soil. With each tip, a small amount of water flows into a sample bottle. Every second week a water sample is analysed for various substances, with the emphasis being on nitrate. 

Some lysimeters stand on a scale which records their weight every 5 minutes. Through changes in weight and the seepage volume, the amount of precipitation and evapotranspiration over a given period of time can be calculated. The collection of this data and the measurement of water content at different lysimeter soil depths via probes, provides information on the water consumption of crops.



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