Effects of ZnSO 4 and Zn‐EDTA applied by broadcasting or by banding on soil Zn fractions and Zn uptake by wheat ( Triticum aestivum L.) under greenhouse conditions

Zinc biofortification of staple food crops is essential for alleviating worldwide human malnutrition. Agronomic interventions to promote this should include fertilizer selection and management. A chelated Zn source, Zn‐EDTA, and an inorganic Zn source, ZnSO 4 × 7 H 2 O, were applied either by banding or by broadcasting in soil, and Zn fractions in soil and Zn uptake by wheat were determined in a pot experiment. Compared to ZnSO 4 × 7 H 2 O, Zn‐EDTA produced higher Zn concentration in grain regardless of application method and even at a lower application rate. Residual Zn fraction was the largest Zn fraction with both ZnSO 4 and Zn‐EDTA amendment. ZnSO 4 banded in soil caused Zn fractions to be restricted to the Zn‐amended soil band and resulted in lower grain Zn concentrations than did broadcast ZnSO 4 . Planting wheat slowed Zn fixation by promoting the maintenance of a high concentration of Zn fraction loosely bound to organic matter (LOM‐Zn) in soil. Zn‐EDTA was a better Zn source for Zn biofortification of wheat than was ZnSO 4 .