Konstruktion eines Waldlysimeters zur Untersuchung des Stickstoffhaushales mit 15N

Irdning

1999

1 Abb., 11 Lit. Ang.

Artikel aus einem BuchUnselbständiges Werk

200107274

The design of a lysimeter for a 15N tracer study in a forest ecosystem for estimation of nitrat leaching is described. The zero tension lysimeter consists of a soil monolith surrounded by a fiberglass cylinder with a cross section of 0.5 m2 and a height of 0.65 m. On the bottom of a soil pit a metal frame was pressed horizontally into the subsoil. Soil material between the frame was removed and a stainless steel tank for leachate collection was placed into the tunnel inside the frame, which was afterwards refilled. The fiberglass cylinder was stepwise sunk into the ground. This technique made it possible to install a lysimeter on a site hardly accessible by car or truck and to minimize danger of preferential flow due to stones and large plant roots. First results show quite high Delta 15N values in leachate already within three month after application of the tracer. The amount of nitrogen leached is smaller than 0.1 % of total nitrate -N in the leachate and does not influence transformation processes in soil.