Stubble catch crops are currently appreciated mainly because of their beneficial effect on the soil environment. It manifests itself through limiting the risks of eutrophication caused by the leaching of soil nutrients, especially nitrogen and potassium. Catch crops uptake assimilable forms of elements from the soil and store them in their biomass during autumn and winter. The mass of nutrients accumulated in stubble catch crop biomass depends on their content in the plant and yield of biomass. A field study aiming to evaluate the effect of the sowing time of stubble catch crops on the content and uptake of macroelements was carried out in Mochełek near Bydgoszcz, in 2013-2015. The experiment was set up on Luvisol soil and involved three cultivated crops (white mustard cv. Warta, common buckwheat cv. Panda and common vetch cv. Fama) sown at 2 dates (early – 08-12.08, and delayed – 10 days after the early time). The tested plants varied in the potential of taking up elements from soil, which was very high for potassium (from 28.27 kg ha-1 K in buckwheat to 65.24 kg ha-1 K in mustard) and nitrogen (from 17.61 kg ha-1 N in buckwheat to 64.94 kg ha-1 N in vetch). Phosphorus and magnesium were taken up by plants in small amounts, namely 5.413 kg ha-1 P and 3.257 kg ha-1 Mg. Vetch surpassed the other plants in terms of the content and uptake of N and P. Mustard took up most K, whereas buckwheat was superior to the other species in the uptake of all the assessed elements in biomass as well as the content of N, P and K in both aerial parts and postharvest residue. A delay of catch crop sowing by 10 days resulted in a significant decrease in the N, P, K, Ca and Mg uptake by plants. Vetch showed the strongest response to this factor, and mustard - the weakest.

23.1.2018