Zn-DTPA-HEDTA-EDTA Application: a Strategy to Improve the Yield and Plant Quality of a Barley Crop While Reducing the N Application Rate

Abstract

Over-use of N fertilization has been common in order to obtain the highest possible grain yield. We investigated the efficiency of combining the application of N and ZnCHE (Zn-DTPA-HEDTA-EDTA). Different rates (30, 60, or 90 kg ha−1) and sources [pig slurry(PS) or urea] of N and rates of ZnCHE (0, 0.5, 1, or 1.5 kg ha−1) were applied to a barley crop. Nitrogen fertilization combined with soil Zn applications had a significant interaction on various plant parameters (grain protein concentration, yield, Zn uptake, and N uptake). An application rate of 90 kg N ha−1 seems recommendable to obtain high values for both crop yield and N uptake by the plant. PS application was associated with higher mean grain yield and Zn utilization than urea application, but with lower grain protein concentration. On the other hand, the lowest Zn application rate was sufficient to achieve a high grain yield (> 3200 kg ha−1). Higher Zn rates provided great Zn concentrations in the different parts of the plant. Furthermore, high grain protein concentrations (> 9.6%) were obtained with combinations of N60 or N90 and ZnCHE-1 or ZnCHE-1.5, both for PS and for urea. The application of this synthetic Zn chelate could be recommended as a strategy for reducing the N application rate but still obtaining high grain yield and nutritional value in barley. These effects may have been due not only to Zn application but also to the influence of chelating agents such as DTPA, HEDTA, and EDTA.