Among other things the plants quality can be assessed on the basic of quantitative nutrient ratios. Moreover the proportions and relationship between macronutrients in plant biomass can be an indicator of vegetation composition and nutrient limitation. The research deals with the influence of soil amendment with mineral, organic and mineral-organic fertilisation on quantitative changes in nutrient ratios determined for seeding camelina, white mustard and spring barley cultivated on light soils in subsequent years. A 3-year pot experiment was conducted with two doses at a the rate equivalent to 70 kg N ha-1 (I) and to 170 kg N ha-1 (II). Plant materials were subjected to chemical analyses to assess their macronutrient contents and based on these data mutual proportions of individual nutrients were calculated. Changes in ratio values were visualised using statistical tools, i.e. multivariate analysis of variance MANOVA and standard analysis of variance ANOVA. Regardless of applied fertilisation, white mustard showed the highest values of most calculated nutrient ratios, although only for spring barley the values of nutrient ratios were consistent with those given in literature as adequate. Generally the fertilisers applied in a dose equivalent to 170 kg N∙ha-1 resulted in higher values of nutrient ratios, which was observed especially in the case of NPK. The study clearly demonstrated that the plant species diversity as well as fertilisation play a crucial role in quantitative changes of nutrient ratios. It is worth stressing that both organic fertiliser and mineral-organic fertiliser similarly affected nutrient ratio values.

25.3.2020