The effect of soil type and soil additives on the selected growth parameters and yield of flowerheads of Calendula officinalis L.
Introduction: Soil additives, which usually contain nutrients and microorganism, can improve soil conditions for plants. There are still few papers dedicated to the application of soil additives in herb plants, especially in calendula. Objective: The aim of the study was to determine the effect of selected soil additives on growth and yield of calendula. Methods: In a pot experiment first order factor was a type of soil: mineral soil with straw, mineral soil and organic soil. The second order factor was soil additive: control, UG Max, EM1 and PRP SOL. Results: The application of UG Max and PRP SOL increased the yield of dry matter of flowerheads by respectively 48.1% and 46.3% in comparison with the control group. Conclusions: UG Max and PRP SOL proved to be the most useful soil additive for calendula growing. The effect of UG Max and PRP SOL was particularly good on organic soil.