The effect of different zinc sources and application methods on the yield and quality characteristics of soybean (Glycine max. L.) under field conditions in the Çukurova Region thesis title

In this study, the effects of different zinc sources and application methods on yield and quality characteristics of soybean plants were investigated under field conditions in Çukurova Region. The study was carried out in 2023 in a randomized block split-plot experimental design with four replications. In the study, ZnSO47H2O, ZnCl2 and Zn-EDTA fertilizers were applied by three different methods as soil (1kg da-1), foliar (0.2%) and soil (1kg-1) + foliar (0.2%). At the end of the study, it was observed that Zn application methods and fertilizer sources had no significant effect on yield. When both Zn source and application method were taken into consideration, it was determined that higher yield values than the control application were only in soil ZnCl2 application among all treatments, and the grain yield increase due to soil ZnCl2 application (429 kg da-1) was approximately 0.7% compared to the control application (426 kg da-1). In contrast to these findings, Zn sources were found to have a significant role only on crude oil content among the quality parameters. The highest increase in crude oil ratio (3.7%) was obtained from ZnSO4 fertilizer application compared to the control treatment. On the other hand, Zn application methods were found to be insignificant on crude oil yield, crude protein ratio and crude protein yield values. Plant height was affected by Zn sources at 5% significance level. The highest increase was obtained from ZnCl2 source with 12.16% compared to the control treatment. It was determined that the Zn application method on the number of pods in soybean was significant and the highest number of pods was in foliar (Y) Zn application with 34.9 pieces. Zinc treatments had insignificant effects on parameters such as first pod height, number of grains in pods, number of grains per plant, 100 grain weight and plant biomass. Different from these results, it was observed that Zn fertilization improved Zn and N nutrition of soybean plants. Zinc application methods were found to have a significant effect on grain Zn concentration at 5% level. The most effective method was the combination of soil and foliar applications (T+F). As a result, it was concluded that although zinc applications had positive effects on some quality parameters of soybean plants, they did not provide a significant increase in yield. When zinc application methods and sources were evaluated together, it was found that ZnCl2 and soil+leaf application generally increased growth and yield parameters of soybean.