Desorption examinations were carried out in the soil samples taken from the ploughed layer during the vegetation period in a winter wheat fertilisation experiment on calcareous chernozem soil with the aim to follow how calcium and magnesium gets incorporated into the soil solution.

Calcium desorption measured in aqueous flow

Fertilisation significantly increased the amount of desorbed calcium in comparison with the control treatment only in the NK1 treatment in the average of fractions, and the same observations were gained in NK1 and NP2K2 treatments in the 5-minute fractions.

The intensity of desorption is quick in the average of fertilisation treatments and the highest values – half of the total amount – were measured in the first fraction, while the change in further fractions is quick and significantly lower.

Magnesium desorption measured in aqueous flow

The length of fractionation time strongly affected the process – the highest values were measured in the first fraction – and the further increase of its duration resulted in intensive slow-down.

In the average of fertilisation treatments and also within each fraction, desorption showed significant differences on the soil which was properly supplied with magnesium only in the shortest (5 minute long) fraction in the NK1 and NP2K2 treatments in comparison with the non-treated one. Seasonal dynamics changed in accordance with solubility, mostly environmental factors (solubility in the soil, temperature, moisture) with small differences in the case of both elements.

The results of the developed examination method show the perspective possibility of its use in the control of dynamic nutrient supply, while they also justify the broadening of examinations and the further refining of the method itself.

Keywords: desorption, constant fluid flow process, fertilisation, winter wheat