Teresa Bowszys

Effect of the application of sewage sludge compost on the content and leaching of zinc and copper from soils under agricultural use

Municipal sewage sludge can be used in agriculture provided that the permissible levels of heavy metals are not exceeded in either the sewage sludge or in the top layer of soil to be amended by this substance, and that its application does not deteriorate the soil quality. The purpose of this study was to determine the effects of different forms of sewage sludge on the content of Cu and Zn in soil and in soil leachate. The study comprised 2 rotations (potato, spring barley, winter oilseed rape, winter wheat). Each series was composed of the following treatments: NPK, FYM, municipal sewage sludge composted with straw, dried and granulated municipal sewage. FYM and composted sewage were applied once in the rotation (under potato) in a dose of 10 Mg d.m. ha-1 and twice (under potato and under winter oilseed rape) in a dose of 5 Mg d.m. ha-1. In the other years (under spring barley and winter wheat), soil received only mineral fertilization. In order to evaluate the effect of the composts on the leaching of Cu and Zn from soil, a lysimetric experiment was conducted under controlled conditions. Before the experiment, the soil content of Cu was low (1.47 mg kg-1) and Zn was medium (10.11 mg kg-1). The content of copper in the composts ranged from 4.5 to 340.1 mg kg-1 d.m. and that of zinc was from 109.5 to 1310.1 mg kg-1 d.m. The composted sewage sludge significantly raised the soil content of available forms of Cu and Zn, but did not change the soil nutrient abundance class. Fertilization modified the content of the microelements in the soil leachate.

Wpływ nawożenia mineralnego na zawartość i jakość tłuszczu w niełupkach ostropestu plamistego (Sylibum marianum L. Gaertner)

The basis of research was a two-factorial pot trial set up in a completely random design with four replications. A uniform PK fertilization regime investigated the effect of increasing fertilization level of nitrogen, sulfur and boron on the content of crude fat and fatty acid profile in achenes of two forms of the milk thistle – cultivar Silma and a population cultivated in Poland. The average content of fat in milk thistle achenes cv. Silma was 246.0 g·kg -1 d.m. and was significantly lower than in achenes form population (264.7 g·kg -1 d.m.). The fat content in achenes cv. Silma decreased with increasing levels of nitrogen fertilization, whereas population plants contained similar amounts of fat, regardless of the level of this component fertilization. The level of nitrogen fertilization to a greater extent modified the profile of fatty acids in the oil from population plants than cv. Silma. Compared with plants not fertilized with this component, after application of the lowest dose of nitrogen (1 g per pot), in the oil obtained from population plants oleic acid increased by 6.5%, and linoleic decreased by 9.7%. The addition of sulphur increased share of linoleic acid (C18:2) and decreased oleic (C18:1) in oils of both forms of milk thistle.