Plant Soil Environ., 2012, 58(9):424-428 | DOI: 10.17221/314/2012-PSE

Nodulation of lucerne (Medicago sativa L.) roots: depth distribution and temporal variation

F. Li¹, T. Kautz¹, R. Pude², U. Köpke¹

¹ Institute of Organic Agriculture, University of Bonn, Bonn, Germany

² Research Center Campus Klein-Altendorf, Rheinbach, Germany

This study was undertaken in order to test whether the development of nodule density over the vegetation period is different in lucerne stands grown for 1, 2 or 3 years continuously. For rapidly assessing nodule density in the field, a modified profile wall method was applied. Nodules were counted on a vertical profile wall, after spraying away a 2 cm layer of soil. For validating this method nodule density was determined on roots washed from monolith samples. Field data indicate that there is a shift of nodulation towards deeper soil layers with increasing maturity of lucerne stands. In 1-year lucerne nodulation was limited virtually to the top 15 cm of soil. In the 15-30 cm soil layer and in the subsoil (30-80 cm), nodule density increased with the cropping duration (1 year < 2 years < 3 years). Temporal decreases in nodule density during the vegetation period associated with dry spells were more pronounced for 2-years as compared with 3-years lucerne.

Keywords: alfalfa; perennial cultivation; profile wall; soil monolith; subsoil

Published: September 30, 2012  Show citation