Methods for quantification of root distribution pattern and root dynamics in the field

For a functional evaluation of root systems in the field, two aspects deserve spacial interest and require separate methods for their study.
A. Spatial root distribution: heterogeneity of total root density in relation to planting pattern, soil structure, and heterogeneity of nutrients supply. Recently such heterogeneities have become the subject of research as such and are no longer treated as merely a nuisance is establishing in effects of experimental treatments on average root densities. On a detailed level the degree of actual soil-root contact has become of interest.
B. Roots dynamic in time: root growth and decay in the field can hardly be studied by destructive means, due to the large spatial heterogeneities. They have to be quantified by repeated observations of the sam roots, under conditions which approach field conditions as mush as possible.
For both types of information additions to and improvements of classical techniques are given: relations between root basic parameters, sampling schemes, quatification of root anisotropy, quantification of pattern in root distribution, quantification of soil-root contact and the minirhizotron technique for quntifying root dynamics.