Meta-Analysis on Research Results of the Effect of Manure, Biological and Nitrogen Fertilizers on Sugar Beet Quantitative and Qualitative Traits

The quantity and quality of sugar beet root impurities, especially sodium, is one of the factors affecting root quality and extraction coefficient of sugar (ECS) from sugar beet. Various factors such as soil conditions, application time, and quantity of different fertilizers have effects on the amount of sugar that can be extracted in the factory. Data and results obtained from researches conducted during 1997-2021, which were published in 30 final reports in Sugar Beet Seed Institute (SBSI), were analyzed in order to investigate the factors that affected sugar beet impurities and its quantitative and qualitative traits. The data of these reports were created in a database containing 480 rows and 26 columns. The data corresponding to the investigated treatments included manure, bacterial products and amino acids, and time and amount of nitrogen application were extracted from the database. Then, the reaction ratio (the ratio of trait changes in each treatment to the control in the same experiment), average of the reaction ratio, standard deviation, and the significant effects of the contribution of each factor to sugar beet root traits were determined. The results of the meta-analysis studies showed that consumption of 60 t/ha of manure, 150-200 kg/ha nitrogen, and the split application of 25% of N-fertilizer before planting, 50% during thinning, and 25% during the second thinning, increased root, sugar, and white sugar yields significantly, while sodium content in sugar beet roots did not change significantly. Excessive use of nitrogen (i.e. 250-300 kg/ha) and use of all nitrogen fertilizer after planting increased root sodium content by, respectively, 18% and 7.5%, while reducing yield. The bacterial product and amino acid only increased the sugar content by about one percent.