Soil application of zinc fertilizer could achieve high yield and high grain zinc concentration in maize

Abstract

Increasing both yield and grain zinc (Zn) concentration (GZC) are the two important goals of maize production in China and elsewhere in the world. However, it is not clear whether soil application of Zn fertilizer could realize high yield and GZC. The current study aimed to examine how soil Zn application affects yield and GZC and what is the optimal DTPA-Zn for high yield and GZC requirement. A 3-year field experiment with Zn fertilizer application rates of 0, 10, 25, 50, 100, 150 kg ZnSO4•7H2O ha−1 was conducted. Soil Zn application significantly increased soil DTPA-Zn concentrations, maize yield, GZC and kernels number per spike; and decreased the length of barren ear tips. In each of these cases, the level of response was highly related to the quantity of Zn added to soil. The optimal soil DTPA-Zn concentration was 4.7 mg kg−1 required to attain high yields and was 7.6 mg kg−1 required to attain high GZC, respectively. Soil Zn fertilization can increase simultaneously both grain yield and GZC and achieved the biofortification of maize with Zn, and its realization depended on the available Zn concentrations in soil.