Fig. 4.
Rainwater distribution patterns in the vertical soil section (20 cm deep, from the bottom of furrow) perpendicular to crop lines were illustrated by Brilliant Blue FCF dye-tracing under different cropping systems, 24 h after simulated rain for 2, 4, and 6 min, respectively. FP: flat plot; RF: ridge–furrow; FMRF: film fully mulched ridges–furrow. Each of 9 pictures was overlapped by using three images from respective triplicate plots. The assumed maize densely-rooted zone was circled in each of 9 pictures, which had a radius of 10 cm, with the location of seed placement (5 cm in depth) as the center.