Our research work was carried out in the Westsik crop rotation field experiment in 2018. The main research purpose was to analyse the effect of the different organic and chemical fertilizers on parameters of rye. Our results revealed some differences between the different fertilization methods. One spike weight, grain weight of one spike, r...ye plant height, rye plant weight per m2 and 1000 seed weight in crop rotations VII, XV and VIII were different from the data of all crop rotations. This finding can be explained by the fact that crop rotations VII and XV were non-fertilized, only 23.3 t ha-1 straw manure (VII) or green lupine manure was applied as a second crop (XV). In addition, crop rotation VIII consists of four parts where we apply chemical fertilization with green lupine manure as a main and second crop. There is a positive close correlation between rye plant height and other studied characters (rye plant weight per m2, spike length, weight of one spike, grain weight per spike, spike weight per m2, grain weight per m2 and 1000 seed weight).
The primary purpose of our experiment was the solution of municipal excess sludge treatment by a renewable energy resource used willow (Salix viminalis L.) plantation. Tests were carried out to state whether the applied sewage sludge has caused any accumulation of the toxic elements in the studied soil layers, and - based on the results –to s...ee whether the plantation is suitable for the treatment of municipal sewage sludge.
The excess sludge (sludge before dewatering) is beneficial for the willow, because it contains a 3–5% dry matter and therefore, a lot of water, too. This high water content ensures the high water amount needed for the intensive growth of the willow. On the other hand, the wastewater treatment plant can save the dewatering cost which corresponds to about 30% of the water treatment process costs. The amounts of the sprinkled sewage sludge were calculated on the basis of its total nitrogen content. Treatments were the followings: control, 170 N kg ha-1 year-1 and 250 N kg ha-1 year-1. The mean values of the toxic element concentrations in the sewage sludge did not cross the permitted limits of the land accommodating.
The measured toxic element values of the soil were compared to the limits of the 50/2001. (IV.3.) Government Regulation.The sprinkled sewage sludge on the bases of the total N content did not cause accumulation of heavy metals in the soil and the treated plants were also healthy without any signs of toxicity.