Assessing Crop Response to Zinc Fertilization: a Meta-Analysis

Abstract

Several studies on effects of Zinc fertilization on cereals yield and their Zinc content on soils with various soil properties and using different Zn fertilization strategies have been conducted. Nevertheless, studies that summarized the studies in the form of meta-analysis as to what extent the crop Zn content and grain yield could be improved as result of Zn fertilization were limited. Hence, the objective of this study was to evaluate the response of cereal crops to Zinc fertilization across selected soil properties and Zinc fertilization startegies from large number of published studies through a meta-analysis. Fourty-two field experiments, from 27 peer-reviewed published articles were included in the analysis. MetaWin v 2.1 was used for the analysis and effect sizes estimated by using the natural logarithm of response ratio method. Cumulative analyses of each study showed a positive and significant effect of Zn fertilization over no Zn fertilization on Zn content and grain yield of agricultural crops. The average Zn content and grain yield of crops across studies is found to be 12.6; 20.4 mg/kg, and 3526; 4370kg/ha, respectively for no Zn vs Zn applied treatments; corresponding to approx. 62% and 24% increase in Zn content and grain yield as result of Zn application. In general, in Zn deficient areas, Zn biofortification through Zn fertilization of the soils can be used to improve crop Zn content and grain yield significantly. Moreover, other factors such as application methods, soil pH, SOM, and P should be managed integratively for successful Zinc biofortification.