Wheat root system architecture and soil moisture distribution in an aggregated soil using neutron computed tomography

Abstract Non-invasive techniques are essential to deepen our understanding of root-soil interactions in situ. Neutron computed tomography (NCT) is an example of such techniques that have been successfully used to study these interactions in high resolution. Many of the studies using NCT however, have invariably focused on lupine plants and thus there is limited information available on other more commercially important staple crop plants such as wheat and rice. Also considering the high neutron sensitivity to hydrogen (e.g. water in roots or soil organic matter), nearly all previous in-situ NCT studies have used a relatively homogeneous porous media such as sand, low in soil organic matter and free from soil aggregates, to obtain high-quality images. However to expand the scope of the use of NCT to other more commercially important crops and in less homogenous soils, in this study we focused on wheat root growth in a soil that contained a considerable amount of soil organic matter (SOM) and different sized aggregates. As such, the main aims of this research were (1) to unravel wheat (Triticum aestivum cv. Fielder) root system architecture (RSA) when grown in an aggregated sandy loam soil ( Fig. 1 ). This highlights the importance large macro-aggregates in sustainable soil management as they may be able to provide plants water during periodic dry spells. More in situ investigations are required to further understand the impact of different aggregate sizes on RSA and water uptake.