Effects of ZnSO₄ and Zn‐EDTA applied by broadcasting or by banding on soil Zn fractions and Zn uptake by wheat (Triticum aestivum L.) under greenhouse conditions

Abstract

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, ZnSO4 × 7 H2O, 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 ZnSO4 × 7 H2O, 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 ZnSO4 and Zn‐EDTA amendment. ZnSO4 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 ZnSO4. 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 ZnSO4.

Comparison and modelling of extraction methods to assess agronomic effectiveness of fertilizer zinc

“…The single nutrient (Zn‐only) fertilizers usually consist of zinc oxide (ZnO), zinc sulfate (ZnSO 4 ) or zinc oxysulfate, which is made by partial acidulation of ZnO with sulfuric acid. Chelated Zn sources can be more effective than traditional formulations in high pH soils ( Zhao et al., ), but their high cost often makes their use uneconomical ( Goos et al., ). The agronomic effectiveness of Zn‐only fertilizers in granular form has been found to be related to their solubility, i.e ., high for ZnSO 4 , low for ZnO, and intermediate, depending on the degree of acidulation, for Zn oxysulfate ( Mortvedt , ; Amrani et al., ).…”

Co-application of molybdenum and zinc increases grain yield and photosynthetic efficiency of wheat leaves

“…However, some of the wheat-growing areas in Western Australia and China are severely deficient in Mo, which restricts wheat production (Brennan 2006, Sun et al 2009. Zn deficiency is one of the most important factors affecting wheat production globally, particularly in Turkey and China (Zhao et al 2019). The seed yield of chickpea was increased by co-application of Zn, boron, and Mo, and there was a low significant Zn × Mo interaction on chickpea yield (Valenciano et al 2010).…”

Agronomic biofortification of food crops: An emerging opportunity for global food and nutritional security

“…Chelated nutrients have reduced environmental loss. Zhao et al (2019) found that Zn-EDTA fertilization achieved greater Zn biofortification than ZnSO 4 .7H 2 O fertilization, even with a lower treatment volume, in a greenhouse study. Zinc content in wheat was increased by foliar application of Zncontaining salts and Zn chelates (e.g., ZnSO 4 , Zinc-EDTA, generally @ 0.5-0.7 kg/ha) (Kutman et al, 2010;Zhao et al, 2014).…”