Zawartość podstawowych składników pokarmowych w buraku cukrowym uprawianym w różnych systemach nawożenia w drugiej rotacji płodozmianu

A field study was carried out in 2000–2002 in the second rotation of two factors crop rotation experiment (sugar beet – spring wheat – winter barley) established at Swojec Experimental Station of Agricultural University of Wrocław. It was conducted as split-block method in four replications. The objective of this study was to compare the content of basic mineral components (total nitrogen, phosphorus, potassium, calcium, magnesium) in roots and leaves of sugar beet (Kujawska cultivar). The following organic fertilization in sugar beet cultivation was used: treatment 1 – without fertilization, treatment 2 – manure once every third year, treatment 3 – ploughed down stubble crop under sugar beet with every year ploughed down by-products of forecrops (after winter barley and spring wheat – 5 t ha-1 of straw with addition of 50 kg ha-1 nitrogen, after sugar beet – 40 t ha-1 of sugar beet leaves), treatment 4 – 10 t ha-1of vermicompost under sugar beet. Increasing level of nitrogen fertilization – 0, 50, 100, 150 and 200 kg N ha-1 was the subplot of experiment. Lack of organic fertilization increased the content of total nitrogen, phosphorus and potassium in roots of sugar beet. The lowest content of the examined components in roots of sugar beet growing under manure was observed. The increasing level of nitrogen fertilization decreased the content of total N, but it was unequivocal for other components. The content of nitrogen in sugar beet leaves was not modified to a large extent by the used nitrogen fertilization. The content of phosphorus and magnesium was significantly higher in sugar beet leaves growing without organic fertilization or with manure compared to the treatments where stubble crop and vermicompost were used. The content of potassium was significantly depended on nitrogen fertilization. Application of manure increased the content of that component. Plots without organic fertilization were characterized by the lowest content of K