Sorption Capacity of Sandy Soil Under Long-Term Fertilisation

In this paper, the results of an investigation of the effects of particle-size distribution, soil organic matter content and its parameters on soil sorption capacity are presented and their mutual relationships in sandy soils under long-term fertilisation experiments are determined. Soil samples were taken at the experimental station of Warsaw University of Life Sciences located in Skierniewice, (Poland) in spring 2017. The study included 94- and 41-year-old experiments with mineral fertilisation (no fertilisation, NPK, CaNPK) and 25-year-old experiment with mineral fertilisation + farmyard manure (FYM) in 4-year cycle: FYM, FYM+NPK and FYM+CaNPK. The results show that in the 94-year-old experiment in NPK and CaNPK treatments, hydrolytic acidity (Ha) decreased in comparison with the control by 30% and 88%, respectively, while in 25- and 41-year-old experiments only the application of NPK significantly increased Ha values. The sum of basic cations increased by a factor of 10 at the most in the CaNPK treatment in the 94-year-old experiment. The same effect was also observed in the 25-year-old experiment. On the one hand, the sorption complex gradually became fully saturated as a result of fertilisation in the 94-year-old experiment. On the other hand, in the 25- and 41-year-old experiments, base saturation was substantially reduced. A higher humus stability was an important agent for improving soil sorption capacity in 41- and 94-year old experiments.