Coring systems - MR tube INSTALLATION

Artificial grassland, roots in a mesocosm experiment. (c) Image property of Boris Rewald (BOKU)

A tight and gap-less fit of MR tubes to the surrounding soil (as in the example on the left hand side) is paramount for correct observations, preventing artificial root growth in gaps and alongside the tube. Manual auger type of soil corer are generally not suitable to install MR tubes in situ due to the rough surface produced during drilling. Instead we recommend to use soil corers with sharp cutting edge and with a slightly smaller diameter for best results. Vienna Scientific and Bartz Technology Corporation supply soil corer sets suitable to install the chosen MR-T type to a depth of approx. 1 m (depending on brawn ;) and soil skeleton of course). We currently do not offer mechanised/tractor-mountable drilling devices for deeper installation of MR tubes. Researchers need to make a informed decision about the required diameter of the MR corer. As a rule of thumb, the outer diameter of the soil corer should be 2-4 mm smaller than the used MR tubes' outer diameter, however, this depends on soil physical properties. In soils tending to shrink when drying, i.e. with a high content of loam, a larger difference between corer and tube size (i.e. a relatively smaller-sized corer) might ensure a tighter fit under dry soil conditions (at the price of a more difficult installation and potentially more tube scratching). If MR tubes should be installed at a certain angle (e.g. 45°), an alignment frame to position the soil corer correctly is recommended.