Changes in Soil Sulfate Sulfur Content as an Effect of Fertilizer Granules Containing Elemental Sulfur, Halloysite and Phosphate Rock

With a shortage of sulfur in the soil and an increasing world population and, thus, food consumption volume, the demand for this important nutrient is likely to increase, both globally and regionally. The purpose of this model incubation study was to evaluate the effect of fertilizer granule applications containing elemental sulfur, halloysite and phosphate rock on the content of the bioavailable form of sulfur and phosphorus, as well as dehydrogenase activity and pH value of two soils differing in granulometric composition and chemical parameters. In addition to the standard procedure of analysis of variance, the authors propose various methods of advanced statistical analysis: regression modeling, including simple regression and multiple regression, or multivariate methods of grouping objects and traits resulting in the creation of heatmaps. With respect to the control, the application of fertilizer granules generally had no significant effect on the content of available phosphorus and the activity of dehydrogenase, and had little effect on the degree of acidity of the soils tested. There was a greater effect of introducing fertilizer granules on the content of sulfate sulfur in heavy soil than in medium soil. Using advanced statistical techniques revealed relationships between the studied soil parameters and changes in their values as affected by the experimental factors.