Impact of manure and organic fertilizers on the quantity and content yield of heavy metals in spring rape

Abstract

The pot experiment was set up with the split plot method in three repetitions in 2006. The objects of the first factor were the doses of manure and organic fertilizers to the soil in conversion to the brought in nitrogen (85 and 170 kg N·ha -1 ), the objects of the second factor were the types of fertilizers: manure, sewage sludge and the composts prepared from sewage sludge. The soil used in an experiment was supplied from The Agricultural Experimental Station in Lipnik. The soil was taken from the arable layer, it has the granulometric composition of the light loamy sand. The content of available phosphorus, potassium and magnesium formed on medium level, the pH KC l of the soil amounted to 5.13. The soil was characterized by 0 0 contamination of trace elements, which means that it contained the natural content of cadmium, copper, nickel, lead and zinc. Spring rape var. Licosmos was the test plant. The aim of the research was the assessment of the influence of manure, sewage sludge and compost prepared from sewage sludge on yield quantity of seeds and straw and the content of cadmium, nickel, lead and zinc in spring rape. The conducted research shows that fertilizers brought into the soil (manure, sewage sludge and compost prepared from sewage sludge) as well as two levels of fertilizing had a significant influence on the yield of the seeds and straw of spring rape. Manure, sewage sludge and compost prepared from sewage sludge played less significant influence on the decreasing or excessive increasing of heavy metals concentration in the seeds of spring rape. The double dose of fertilizers caused higher accumulation of heavy metals in the test plant. The straw of spring rape should be treated as a source of organic matter and the main nutrients for the soil. The highest concentration of copper, manganese, nickel and zinc in the straw of spring rape was noticed after the application of sewage sludge and of cadmium and lead after the application of compost prepared from sewage sludge.

The influence of composts on potato tuber, spring oilseed rape seed and threshing residue yields and concentrations of chemical elements in them

“…A higher Ni concentration in rape seeds was achieved by fertilising with green waste compost and that in threshing residues -with biogas production waste and sewage sludge composts. Nickel concentration increases were not significant compared to those reported by other researchers, when having applied sewage sludge compost the resulting Ni concentration in rape seeds amounted to 2.58-2.86 and that in threshing residues was 1.50-1.54 mg kg -1 (Krzywy, Iżewska, 2007).…”

“…Cadmium concentrations in spring oilseed rape seeds and threshing residues ranged within the limits of 0.034-0.036 and 0.150-0.180 mg kg -1 , respectively. Regardless of the type of compost used, Cd concentrations in rape seeds and threshing residues were within the limits of accepted tolerances and lower compared to the concentrations found by other authors in seeds (0.230 mg kg -1 ) and threshing residues (1.552 mg kg -1 ), when rape had been fertilised with sewage sludge compost (Krzywy, Iżewska, 2007).…”

“…In addition, sewage sludge compost increased Pb concentration in rape threshing residues as well. According to the data by other authors, Pb concentrations in rape seeds after the application of sewage sludge were higher and amounted to 3.33-4.31 mg kg -1 (Krzywy, Iżewska, 2007). Even though direct uptake from soil into a potato tubers is only a minor contribution to tuber Cd content (Reid et al, 2003), they accumulate more Cd than grain (Singh et al, 2012).…”