Zasobność mad żuławskich w makroelementy ogólne i przyswajalne

The alluvial soils of the Vistula delta are among the most fertile in Poland. The aim of this study was to determine the content of total forms of phosphorus, potassium, calcium, magnesium, iron, aluminium and sodium and to evaluate the content of available forms of phosphorus, potassium and magnesium in alluvial soils of the Vistula delta. The total content of macroelements can be arranged in the following order: Fe > Al > Ca > Mg > K > P > Na. The correlation coefficients showed a significant correlation between the content of floating fraction (< 0.02), clay (< 0.002), organic carbon and the total content of the analyzed macroelements. The highest content of the determined macroelements was found in very heavy alluvial soils. The plough layers of the alluvial soils were more abundant in total phosphorus and calcium than the subsoil and parent rock. However, the content of total potassium, magnesium and aluminium was the highest in the parent rock. The content of total iron, phosphorus and magnesium in alluvial soils of the Vistula delta was greater than in the non-alluvial origin soils. Based on the threshold value, the content of available magnesium in the alluvial soils is very high. The content of available magnesium in heavy alluvial soils is significantly correlated with the content of organic carbon. The highest content of available phosphorus (high abundance) and potassium (mean abundance) was found in heavy alluvial soils. Very heavy alluvial soils exhibit mean abundance in available phosphorus and low abundance in potassium. The content of available phosphorus, potassium and magnesium in the total content of these macroelements in the alluvial soils was below 10%. In very heavy alluvial soils, the mean content of available potassium in the total content of this element was very low and it was 4.3% and for phosphorus it was 5.1%. These values are about 1.5 times as low as the values found in heavy and mean alluvial soils