Fig. 4From: Simultaneously maximizing root/mycorrhizal growth and phosphorus uptake by cotton plants by optimizing water and phosphorus managementCorrelation between root length density and hyphal density under different soil water conditions. ** and * indicate a significant difference at the 0.01 and 0.05 levels, respectively (n = 75; P0.05 = 0.226 and P0.01 = 0.294)Back to article page