Organic Wheat Farming Improves Grain Zinc Concentration - Fig 6

Regressions of wheat grain Zn concentration with a) grain yield, b) available P, and c) grain protein concentration. Grain protein concentration had a significant interaction with cropping system on grain Zn concentration; orange shading refers to conventional. P-values for the regressions were all < 0.001 and F-statistics were 17.3, 14.4, and 6.60, respectively. Dotted lines (shaded area) are 95% confidence regions of the regression curves.