Temporal and Spatial Profiling of Root Growth Revealed Novel Response of Maize Roots under Various Nitrogen Supplies in the Field
Figure 5
Soil mineral nitrogen (Nmin; NH4+-N+NO3−-N) in the 0–90 cm soil profile in response to N fertilization in 2007.
The soil samples were obtained using the soil auger method at the same time in each plant harvest. The bars represent the standard error of the mean, n = 4.