“…Recent studies describe the use of ground-penetrating radar (GPR) as a non-invasive means for field root investigations, although the technique is limited to coarse roots (Guo et al, 2013). Apart from these, the minirhizotron technique, which uses a miniature video camera or a scanner to view and record root images through a transparent tube inserted in the soil, is less destructive than coring and enables time-course changes in root growth to be monitored (Upchurch & Ritchie, 1983;McMichael & Taylor, 1987;Smit et al, 2000;Hendricks et al, 2006). This methodology has been widely applied to the study of root dynamics in annual plants (Machado et al, 2003;Yang et al, 2003), forest trees (Day et al, 2006) and fruit trees (Fernández et al, 1992;Abrisqueta et al, 1994Abrisqueta et al, , 2008Wells et al, 2002;Bernier & Robitaille, 2004), as well as for measuring root production and mortality in several tree species (Comas et al, 2000;Crocker et al, 2003), but has been little used for evaluating the response to different crop management practices.…”