Combined zinc and nitrogen fertilization in different bread wheat genotypes grown under Mediterranean conditions

Official URL: http://dx.doi.org/10.1556/0806.44.2016.046

The combined application of nitrogen (N) and zinc (Zn) appears to be a promising agronomic strategy for the biofortification with Zn. To evaluate such efficiency, a field experiment was conducted in south-eastern Portugal under Zn-deficient soil. Four advanced breeding lines and two commercial varieties of bread wheat (Triticum aestivum L.) were fertilized with five treatments: i) control, ii) two foliar Zn applications, iii) one foliar Zn+N application, iv) soil and two foliar Zn applications, and v) soil and one foliar Zn+N application. Grain Zn content varied greatly across treatments and INIAV-1 and the commercial varieties were the most interesting cultivars in all the treatments. Grain Zn concentrations higher than the target level of 38 mg Zn kg(-1) were obtained only when two foliar Zn applications were applied, alone or in combination with soil Zn applications, and grain Zn bioavailability also was more adequate (phytate: Zn ratios similar to 15). Soil Zn application resulted in grain yield increases between 7-10%, which virtually offset the extra application cost. The combined soil and two foliar treatment could be a good option for biofortifying bread wheat under Zn-deficient soils.