Cadmium and Zinc Concentration in Grain of Durum Wheat in Relation to Phosphorus Fertilization, Crop Sequence and Tillage Management

Figure 1

Principal component analysis (based on correlation matrix) of grain yield, grain concentrations of Cd, Zn, Cu, Fe, Mg, K, P, Mn, Ca, grain protein concentration, and selected soil properties (soil P and soil Cd) across 6 site-years. Biplot vectors are trait factor loadings for principal component 1 (PC1) and PC2. Data at each site-year are averaged across P fertilizer treatments.