The use of the ingrowth core method for measuring root production of arable crops - influence of soil and root disturbance during installation of the bags on root ingrowth into the cores

To measure root production by the ingrowth core method mesh bags filled with root-free soil are buried into the root zone of plants. After a time period which should be shorter than the lifespan of the roots the mesh bags are pulled out and root length inside the cores is determined. A major objection against this method is a possible alteration of root growth pattern induced by root injuries or soil disturbances that occur during the insertion of the mesh bags into the soil. Root length density (RLD) in the mesh bags was between 0.7 and 5.0 cm cm(-3) after 14 days of ingrowth of wheat or barley roots depending on soil type or plant age. RLD in the bulk soil next to the mesh bags was between 7.7 and 14.8 cm cm(-3) in the 0-30 cm soil depth. Different time periods between inserting the mesh bags and opening them for root ingrowth in which the installation disturbance could settle, had no effect on RLD in the ingrowth cores. There were also no differences in RLD in the direct vicinity around the ingrowth cores and the bulk soil, which was tested by counting roots at profile walls adjacent to the mesh bags and by taking soil samples around the cores with an auger. The conclusion of these results was that no alteration of root growth pattern occurred in or around the ingrowth cores due to the installation of the mesh bags. However, further investigations are necessary to validate this method as a reliable and easy field method for measuring root growth. (C) 2001 Elsevier Science B.V. All rights reserved.