Bewortelingsonderzoek en ondergrondbewerking in de Noordoostpolder

J.J. Jonker

Research output: Thesisinternal PhD, WU


The aim of this study was to investigate the suitability of the soil layers and profiles for the penetration by roots and of methods of improving root formation by subsoiling.

It was assumed that an adequate moisture supply to the crops required a loam layer at least 70 cm thick penetrable by roots.

Methods for quantitative and qualitative root studies were discussed. Root formation in a homogeneous loam soil profile 100 cm deep was taken as a standard to assess the root systems found in various soil profiles. For some grain crops and winter swede-rape the shoot and root development from germination till harvest were shown in diagrams. Shoot and root quantities were given for winter wheat.

The influences of aeration and texture of soil on root formation and possible causes for poor development were discussed.

After a description of root formation in heterogeneous soil profiles the effects of subsoiling on the roots and yields of several crops were given. Three maps of the western part of the North-East Polder indicate which layers hamper root penetration, and to what depth profiles should be loosened. Areas most badly in need of subsoiling are indicated.

Original languageDutch
QualificationDoctor of Philosophy
Awarding Institution
  • Wageningen University
  • Dewez, W.J., Promotor, External person
Award date27 Jun 1958
Place of PublicationZwolle
Publication statusPublished - 1958
Externally publishedYes


  • tillage
  • ploughs
  • agriculture
  • plant physiology
  • plant development
  • roots
  • botany
  • Netherlands
  • noordoostpolder

Cite this

Jonker, J. J. (1958). Bewortelingsonderzoek en ondergrondbewerking in de Noordoostpolder. Zwolle: Tjeenk Willink.